EP025 Tutorial Collections

EP025

PHYSICS SEMESTER II

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 1 : ELECTROSTATICS

Answer all the questions.

Objective Questions

1. Which one of the following is true about an electric field at a point ?
A. It indicates the electric force per unit mass at that point
B. It indicates the total charge on a particle at that point
C. It indicates the electric force per unit charge at that point
D. It indicates the electric charge per unit mass of a particle at that point

2. The electric field strength at a distance d from a point charge Q is E. What is the electric

field strength at a distance of 2d from a point charge of 2Q ?

A. 1

4

B. 1

2

C.

D. 2

3. At twice the distance from a point charge, the strength of the electric field is
A. Four times its original value
B. Twice its original value
C. One-half its original value
D. One-fourth its original value

4. Figure below shows two parallel plates X and Y that are separated by a distance of 5 cm.

Plate Y is at a potential of -10V. Given that = 200 −1, what is the electric potential at
plate X ?
A. 0 V
B. +10 V
C. +20 V
D. -20 V

5. Which figure correctly shows the equipotential lines around a positive point charge if the
potential difference between successive lines are equal?
A. C.

B. D.

Subjective Questions

1. Charge 1 = +4.00 is located at = 0.200 , charge 2 = +5.00 is at

= −0.300 . Determine the magnitude and direction of the total electric force exerted

by these two charges on a negative point charge 3 = −6.00 that is placed at the

origin. [2.4 µN to the right]

2. Four identical point charges ( = +10 ) are located on the corners of a rectangle as
shown in figure below.

The dimension of the rectangle are = 60.0 and = 15.0 .

a) Sketch the electrostatic forces exerted on the charge at the lower left corner by the

other three charges

b) Calculate the magnitude and direction of the resultant electric force exerted on the

charge at the lower left corner by the other three charges [40.85 N, 83.28⁰

above negative x-axis]

3. Two point charges, 1 = −4 and 2 = −5 are placed 15 cm and 20 cm from the
point P respectively as shown in figure below

Determine [-475 −1]
a) The magnitude and direction of the electric field intensity at P

b) The net electric force exerted on 0 = +1 if it is placed at P
[−4.75 ×

10−4 , ℎ ]

c) The distance of a point from Q1 where the electric field intensity is zero. [16.52

cm]
(Given electrostatic constant, = 9.00 × 109 2 −2)

4. Figure below shows the position of four point charges where = 1 and = 1 .

a) Sketch the electric field acting on point P due to the four point charges

b) Determine the magnitude of the electric field at point P [zero]

5. Initially two electrons are fixed in place with a separation of 2.00 µm. How much work
must we do to bring a third electron in from infinity to complete an equilateral triangle ?

[2.304 × 10−22 ]

6. Two points, A and B are located around a point charge of +3.4 nC as shown in figure
below.

Calculate

a) The electric potential difference between point A and B [-43.56

V]

b) The work done in bringing a charge of -1.5 µC from point B to point A.

[−6.53 × 10−5 ]

7. Two point charges, 1 = −4 and 2 = +5 µ , are placed 4 m and 6 m from a point P
respectively as shown below

a) Calculate the electric potential at P due to the charges. Describe the meaning of the
answer.
[-1500 V]

b) If a charge 3 = +3.0 moves from infinity to P, determine the change in electric
potential energy for this charge.
[−4.5 × 10−3 ]

c) When the charge Q3 is at point P, calculate the electric potential energy for the system of
charges.
[-0.0447 J]
(Given electrostatic constant, = 9.00 × 109 2 −2)

8. A 3 µC particle of mass 0.61 g is travelling horizontally at a constant velocity of 5 ms-1. It
then enters an upward uniform electric field of 2 kN C-1. Explain quantitatively with the
aid of the diagram, the motion of the particle in the electric field.

9. An electron beam enters at right angle into a uniform electric field between two
horizontal plates separated of 5.0 cm apart. The plates are connected across a potential
difference of 1000 V. The length of the plates is 10.0 cm. The beam is deflected
vertically at the edge of the field by a distance of 2.0 cm. Calculate the speed of the
electrons entering the field. [2.96 × 107 −1]

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 2 : CAPACITOR & DIELECTRICS

Answer all the questions.

SECTION A: OBJECTIVE

1. A capacitor with charge Q1 is connected in parallel to a similar capacitor Q2 which
has no charge. Which of the following statement is CORRECT about the capacitors?
A. The total charge for capacitors Q1 and Q2 is the same, the potential difference
across Q1 decreases.
B. The total charge and the total energy for both capacitors are the same.
C. The charge in Q1 decreases whereas the potential difference across Q2 does
not change.
D. The charge in Q2 increases and its capacitance also increases.

2. A simple capacitor is made by placing two oppositely charged conducting plates in
parallel to each other at a distance, d. If the distance between the plates is increases,
what will happen to the capacitor?
A. Increase the charge on its plates.
B. Decrease the charge on its plates.
C. The capacitance increases.
D. The capacitance decreases.

3. In FIGURE 1, determine the energy stored in capacitor C2 if C1 = 25 µF, C2 = 20
µF, C3 = 10 µF and the potential difference at the end of the combination is VAB =
21 V.
A. 0.91 mJ
B. 0.72 mJ
C. 0.40 mJ
D. 0.32 mJ

4.

The capacitor, C in the FIGURE 2 is initially not charged. Which graph represents
the variation of current I with time t after the switch S is closed?

5. A capacitor is charged through a resistor of resistance 2 MΩ. The FIGURE 3 above
shows how the current in the charging circuit varies with time. What is the
capacitance of the capacitor?

FIGURE 3
A. 2.5 µF
B. 5.0 µF
C. 7.5 µF
D. 10 µF

SECTION B: SUBJECTIVE
QUESTION 1

a) In FIGURE 4, given C1 = 3 µF, C2 = 11 µF, C3 = 12 µF, C4 = 6 µF, and C5 = 9 µF.
i. Calculate the effective capacitance of the circuit. [Answer: 6 µF]
ii. If V1 = 12 V, calculate the total charge Q supplied. [Answer: 72 µC]

QUESTION 2
A 15 V battery is connected to three capacitors in series. The capacitors have the following
capacitances: 4.5 µF, 12 µF and 32 µF. Find the voltage across the 32 µF capacitor.
[Answer: 1.39 V]
QUESTION 3

a) Define capacitance.
b) Why electrical energy can still be stored in a capacitor even though the net charge

is zero?
c) How to increases the capacitance of air-filled capacitor without changing its

dimension?
QUESTION 4

FIGURE 4.1 shows an open circuit which consists of a capacitor C1 = 15 µF without
charge and capacitor C2 = 5 µF with 50 µC of charge. S switch is connected to a at time, t
= 0 s.

a) What is the time constant,  during charging for capacitor, C1? [Answer: 7.5 s]
b) Sketch a graph for charge, Q1 induced in C1 against time, t and graph of current I

produced by the battery against time, t.
c) Calculate the charge induced in C1 at time, t = 10 s. [Answer: 66.3 µC]
d) What is the total charge that can be store in C1? By referring to suitable equations,

explain how this value can be influenced by the dielectric constant 1 on the
capacitor. [Answer: 90 µC]
e) Capacitor C1 is let to be fully charged and then S switch is shift to b. After
equilibrium is achieved, what is the potential difference across capacitor C2?
[Answer: 7 V]

QUESTION 5

A capacitor of 2.0 µF is charged using a 1.5V battery. The charged capacitor is then
discharged through a 60kΩ resistor.

a) What is the time constant of the discharged circuit? [Answer: 0.12 s]

b) Calculate the time taken for the charge on the capacitor to decrease to 1 and 1 of
100

its initial value. [Answers: 0.12 s, 0.55s]

QUESTION 6
a) Calculate the value of capacitance for the two pieces of aluminium plane having
area of 1 m2 and separated at 1 cm away in vacuum. [Answer: 885 pF]
b) Parallel plate capacitor in question (a) is filled with material having dielectric
constant value of 5 and potential difference of 10V is applied. Calculate
i. the capacitance value of the capacitor now
ii. the induced charge on the surface of dielectric
iii. the energy stored in the capacitor
[Answers: 4.43 x 10-9 F, 4.43 x 10-8 C, 2.21 x 10-7 J]

QUESTION 7
A 24 µF capacitor is charged to 180 µC. Calculate the additional energy required to charge
the capacitor to 300 µC. [Answer: 1.2 x 10-3 J]

QUESTION 8
Consider a parallel plate capacitor with a capacitance value of C=100 µF; plate area, A =
0.18 m2; and dielectric constant, r = 7.0.

a) Calculate the separation distance between the plate [Answer: 1.12 x 10-7 m]
b) State two ways that can increase the capacitance value without increasing the area

size of the capacitor plate

QUESTION 9

FIGURE 4.2 shows a circuit which is used to charge a capacitor of 50 µF which is initially
without charge. The circuit consists of a voltage source of 12 V, resistor of 800 kΩ, switch
S and galvanometer G.

a) What is the time constant of the charging circuit? [Answer: 40 s]
b) At t = 0 s, switch S is closed and the capacitor is let to charge until saturated.

i. What changes will you observe on the deflection of galvanometer pointer
during the charging process?

ii. Sketch a graph of current, I against time, t.

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 3 : ELECTRIC CURRENT CIRCUITS & DIRECT CURRENT (DC)

Answer all the questions.

SECTION A: OBJECTIVE

1) The terminals of a battery are connected across two resistors in parallel. The resistances of
the resistors are not the same. Which of the following statements is correct?
A The current in the larger resistor is greater.
B The potential difference across the larger resistor is greater.
C The potential difference across each resistor is the same.
D The power delivered to the larger resistor is greater.

2) A wire has a resistance of 5.0 Ω at a temperature of 20.0 °C. If the same wire has a resistance

of 5.8 Ω at 90.0 °C, what is the resistance of this wire when its temperature is -20.0 °C?

A 3.8 Ω C 4.5 Ω

B 4.2 Ω D 4.8 Ω

3) The same potential difference is applied across two wires. Wire A carries twice the current

of wire B. If the resistance of wire B is R, what is the resistance of wire A?

A C 3

4 4

B 2 D
2
3

4) A variable resistor is connected in series with a 25 Ω resistor and a 12.0 V battery. A high
resistance voltmeter is connected across the variable resistor.

V

25Ω

5Ω-15Ω

12.0 V

When the resistance of the variable resistor is increased from 5 Ω to 15 Ω, the reading of
the voltmeter increases from
A 1.3 V to 4.0 V
B 2.0 V to 4.5 V
C 4.0 V to 5.0 V
D 4.5 V to 7.5 V

5) The potentiometer circuit shown is used to determine the e.m.f. of a cell, E1 . The balanced
point could not be found along the slide wire AB.
Driver cell, E Rheostat

A
B

G
R E1
Which of the following procedures would enable the balanced point to be obtained?
A Use a longer slide wire
B Use a more sensitive galvanometer
C Reduce the resistance of the rheostat
D Reduce the resistance R

SECTION B: SUBJECTIVE

6) A current of 4 A flows in the circuit for 3 hours. Calculate the total charges flow in the
circuit. (43200 C)

7) If current of 80.0 mA exist in a metal wire,
(a) How many electrons flow past a given cross section of the wire in 10.0 min? (3 x 1020
electrons)
(b) In what direction do the electrons travel with respect to the current?

8) A 24 V potential difference is supplied to a 15 Ω resistor. Calculate the magnitude of current
flows through the resistor. (1.6 A)

9) An electric heater carries a current of 13.5 A when operating at a voltage of 1.20 x 102 V.
What is the resistance of the heater? (8.89 Ω)

10) A potential difference of 8 V is supplied across a metal wire with uniform cross sectional
area of 0.08 mm2 and length of 0.5 m.Determine the resistivity of the wire if the electric
current flow is 1.2A. (1.07 x 10-6 Ωm)

11) A bird stands on a high voltage transmission wire with its feet 5.00 cm apart. The wire is
made of aluminium with diameter 1.20 cm and carries a current of 55.0 A.
(a) Calculate the resistance of the wire between the bird’s feet. (1.17 x 10-5 Ω)
(b) Calculate the potential difference between the bird’s feet. (6.44 x 10-4 V)
[Resistivity if aluminium = 2.65 x 10-8 Ω m]

12) While taking photographs in Death Valley on a day when the temperature is 58.0 °C, Bill
Hiker finds that a certain voltage applied to a copper wire produces a current of 1.0 A. Bill
then travels to Antartica and applies the same voltage to the same wire. What current does
he register there if the temperature is -88.0 °C? Assume no change occurs in the wire’s
shape and size. (2.3 A)

13) The heating element of an oven is made from a coil of nichrome wire. The oven is connected
to a 240 V power supply with a current of 1.99 A flowing through the coil at initial
temperature of 30 °C. When the oven reaches the operating temperature, the current is 1.77
A. Calculate the final temperature of the coil if the temperature coefficient of resistivity of
nichrome is 4.0 x 10-4 K-1. (340.74 °C)

14) A 6.0 V battery has an internal resistance of 10.0 Ω. The battery is then uses to light a
menthol of 120.0 Ω which is connected in series to a resistor of 40.0 Ω and the potential
difference across the battery is measured once again. What is the reading of the voltmeter?
(5.65 V)

15) Calculate the effective resistance and total current flow from the battery for the circuit
below. (Reffective = 8.94 Ω , Itotal = 1.68 A)

16) Calculate the effective resistance in the circuit below and determine the current flow
through the 1 Ω resistor when the potential difference across points a and b is 120 V.
(2.446 Ω , 49.06 A)

17) The circuit shows two resistors are connected in series with a battery. Calculate the potential
difference across points A and B. (2 V)

18) In the potentiometer circuit below, PQ is a slide wire of length 100 cm and resistance 6.0
Ω. The 1.0 V and 2.0 V batteries have internal resistance 1.0 Ω and 2.0 Ω respectively.
(a) What is the balanced length, l? (0.33 m)
(b) If the resistor 1.0 Ω is changed to 2.0 Ω, determine the new balanced length of the wire.
(0.44 m)

2.0 V, 2.0 Ω

l Q
R
G
P
1.0 V, 1.0 Ω

1.0 Ω

19) A potentiometer with a slide wire XY of length 100 cm is connected to a battery of e.m.f.
2.0 V and is used to determine the e.m.f. ɛ and the internal resistance r of another battery is
shown below.

2.0 V

l Y
X

G

1.0 Ω switch

R

ɛ,r

When the switch is opened, the balanced length is 60.0 cm and when the switch is closed,

the balanced length is 32.0 cm. Determine
(a) The value of ɛ of the battery (1.2 V)
(b) The internal resistance of the battery. (0.875 Ω)

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 4 : MAGNETISM

Answer all the questions.

SECTION A

1. Which of the following statement is not correct?

A The earth has a magnetic field
B The earth’s magnetic field is directed from north to south pole
C The earth’s magnetic field is almost parallel to the earth’s surface at the equator
D The direction of the earth’s magnetic field can be determined by a compass needle

C2, PLO1, MQF, LOD1

2. FIGURE 1 shows two long, straight wires separated by a distance R. Both wires carry
the same current I but in opposite directions. Point P is located midway between the two
wires.

Xy
P

x

R
FIGURE 1

The magnetic field strength at P is given by

A 20I B 0I
R R

C 0I D 30 I
2R 2R

C1, PLO1, MQF, LOD1

3. The magnetic field strength at the centre of a circular coil with N turns is B. If the
number of turns is doubled but the current and radius are each halved, the magnetic field
strength at the centre would be

AB C 2B
B 1B D 3B

2 2

C1, PLO1, MQF, LOD1

SECTION B

1. a) Define magnetic field.
b)
Consider two long and parallel conducting wires separated by a distance d and
carrying current, I. Sketch a resultant magnetic field diagram around the axis of
the wires for the following condition.

i) If the direction of both the current is the same
ii) If the direction of both the current is opposite with each other.

(C2,PLO1,MQF,LOD1)

(ANS: DIY)

2. a) Calculate the magnetic field at a point 2.0 cm from a long straight wire carrying a
b) current of 10 A.

The magnetic field at a point 3.0 cm from a long straight wire is 4.0 10−4 T .
Calculate the amount of current flows into it.

c) A flat circular coil has 10 turns with radius of 5.0 cm. Determine the current must
flows inside the coil if a flux density of 2.0 10−4 T is produced at its centre.

d) A solenoid of length 1.5 m and 2.6 cm in diameter carries a current of 18 A. The
magnetic field inside the solenoid is 2.3 mT. Calculate the length of the wire
forming the solenoid.

(C2,PLO1,MQF,LOD1 (ANS: 110−4 T, 60 A,1.592 A,12.5m )
)

3.
20 cm

4A 6A
FIGURE 2

Two wires as shown in FIGURE 2 carrying current of 4.00 A and 6.00 A in the
direction indicated.

a) Find the direction and magnitude of the magnetic field at a point midway
between the wires.

b) Find the direction and magnitude of the magnetic field at a point midway
between the wires if the current 4 A is in the opposite direction.

(C3,PLO4,MQF,LOD6)

(ANS: 4 10−6 T (out of page), 2 10-5 T (out of page) )

4. A coil of 3 turns with a resistance of 4 Ω connected to a 12 v battery. The radius of the
loop is 1.8 cm.
a) Calculate the amount of current flowing through the loop

b) Determine the magnetic field strength due to each turn at the centre of the
coil.

c) Calculate the net magnetic field strength at the centre of the coil.

[Given: 0 = 4 10−7 H m-1]
(C3,PLO4,MQF,LOD6)

(ANS: 3 A, 1.047 10-4 T, 3.14110-4 T )

5. Two long straight wires are oriented perpendicular to the page as shown in FIGURE 3.
P 5.0 cm

5.0 cm

x I 2 = 4.0 A

I1 = 3.0A
R

FIGURE 3

The current in one wire is I1 = 3.0A pointing into the page and current in the other wire is
I2 = 4.0A pointing out of page. Determine the magnitude and direction of the net
magnetic field intensity at point P.

(C3,PLO4,MQF,LOD6) (ANS: 8.9310-6 T,-63.10 )

6. Calculate the magnitude of the force on a proton travelling 5.0107 ms−1 in the uniform
magnetic flux density of 1.5Wbm −2 , if:

a) the velocity of the proton is perpendicular to the magnetic field.

b) the velocity of the proton makes an angle 500 with the magnetic field.
(Given the charge of the proton is +1.60 10−19 C )

(C2,PLO1,MQF,LOD1 (ANS: 1.210−11 N , 9.1910−12 N )
)

7.

v

A B
5.47cm

FIGURE 4

An electron at point A in FIGURE 4 has a speed v of 2.50 106 ms−1 . Determine

a) the magnitude and direction of the magnetic field that will cause the electron to
follow the semicircular path from A to B.

b) the time required for the electron to move from A to B.

(Given charge of electron, e = 1.60 10−19 C and mass of electron, me = 9.1110−31 kg)

(C3,PLO4,MQF,LOD6) (ANS: 2.610−4T , into the page)

8. Two charged particles with different speeds move one at a time through a region of

uniform magnetic field. The particles move in the same direction and experience equal

magnetic forces. If particle 1 has four times the charge of particle 2, calculate the ratio of

the speeds, v1 .
v2

(C3,PLO4,MQF,LOD6) (ANS: ¼)

9. A wire of 100 cm long is placed perpendicular to the magnetic field of 1.20 Wb
m-2.

a) Calculate the magnitude of the force on the wire when a current of 15 A is
flowing.

b) For the same current in (a), determine the magnitude of the force on the wire
when its length is extended to 150 cm.

c) If the force on the wire in part (b) is 0.6 N and the current flows is 12 A,
calculate the magnitude of magnetic field supplied.

(C3,PLO4,MQF,LOD6) (ANS: 18 N, 27 N, 0.033 T)

10. Two long straight parallel wires are placed 0.25 m apart in a vacuum. Each wire carries a
current of 2.4 A in the same direction.

a) Sketch a labelled diagram to show clearly the direction of the force on each
wire.

b) Calculate the force per unit length between the wires.

c) If the current in one of the wires is reduced to 0.64 A, calculate the current

needed in the second wire to maintain the same force per unit length between

the wires as in (b).

(C3,PLO4,MQF,LOD6) (ANS: 4.6110−6 Nm −1,9.0A)

11. A 50 turns rectangular coil with sides 10 cm x 20 cm is placed vertically in a uniform
horizontal magnetic field of magnitude 2.5 T. If the current flows in the coil is 7.3 A,
determine the torque acting on the coil when the plane of the coil is:

a) perpendicular to the field,

b) parallel to the field,
c) at 750 to the field.

(C2,PLO1,MQF,LOD1 (ANS: 0 Nm, 18.25 Nm, 4.72 Nm)
)

12. a) A rectangular coil of 10 cm x 4.0 cm in a galvanometer has 50 turns and a
magnetic flux density of 5.0 x 10-2 T. The resistance of the coil is 40 and a

potential difference of 12 V is applied across the galvanometer, calculate the

maximum torque on the coil.

b) A moving coil meter has 50 turns coil measuring 1.0 cm by 2.0 cm. It is held in a

radial magnetic field of flux density 0.15 T and its suspension has a torsional
constant of 3.010−6 N m rad-1. Determine the current is required to give a

deflection of 0.5 rad.
(ANS: 310−3 Nm , 1.04 10−3 A)

(C3,PLO4,MQF,LOD6)

13. An electron with kinetic energy of 8.010−16 J passes perpendicular through a uniform
magnetic field of 0.4010−3T. It is found to follow a circular path. Calculate

a) the radius of the circular path.

b) the time required for the electron to complete one revolution.

(Given e / m = 1.761011Ckg−1, me = 9.1110−31 kg)

(C3,PLO4,MQF,LOD6) (ANS: 0.595 m, 8.92 10−8 s)

14. An electron moving at a steady speed of 0.50 106 ms−1 passes between two flat, parallel

metal plates 2.0 cm apart with a potential difference of 100 V between them. The electron

is kept travelling in a straight line perpendicular to the electric field between the plates by
applying a magnetic field perpendicular to the electron’s path and to the electric field.

Calculate

a) the intensity of the electric field.

b) the magnetic flux density needed.

(C3,PLO4,MQF,LOD6) (ANS: 5000Vm −1,0.01T )

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 5 : ELECTROMAGNETIC INDUCTION

Answer all the questions.

OBJECTIVE QUESTIONS
1. Lenz’s law is a statement that

A. The induced emf in a circuit is proportional to the change that produced it.
B. Action and reaction forces prevail in a circuit in which an emf is induced.
C. The direction of the induced emf is in the same direction as the change which

produced it.
D. The direction of the induced emf opposes the change that produced it.

2. A circular coil lies flat on a horizontal table. A bar magnet is held above its center with
its northpole pointing down and released. As it approaches the coil, the falling magnet
induces (when viewed from above)
A. No current in the coil.
B. A clockwise current in the coil.
C. A counter clockwise current in the coil.
D. A current whose direction cannot be determined from the information provided

3. Two coils coupled together possess mutual inductance of 2.0 H. Because of the
occurrence of mutual induction, an emf of 3.0 V is induced in one coil. Then the other
coil must
A. Carry a current of 1.5 A
B. Carry a current that changes at a rate of 1.5 A/s
C. Have a charge of 1.5 C flowing through it
D. Have a potential difference of 1.5 V across it.

4. A circular coil is placed near a straight conductor as shown below. When the current in
the straight conductor increases, the current in the coil is

A. Clockwise
B. Anticlockwise
C. Normal to the plane of the coil
D. None of them

5. Induced emf. produced in a coil rotating in a magnetic field will be maximum when
the angle between the axis of coil and direction of the magnetic field is:
A. 90°
B. 45°
C. 0°
D. 180°

6. When the current through a solenoid increases at a constant rate, the induced current:
A. is a constant and is in the direction of induced current.
B. is a constant and is opposite to the direction of the inducing current.
C. increases with time and is in the direction of the inducing current.
D. increases with time and is opposite to the direction of the inducing current.

SUBJECTIVE QUESTIONS

1. A uniform magnetic field of magnitude 0.50 T is directed perpendicular to the plane of
a rectangular loop having dimensions 8.0 cm by 12 cm. Find the magnetic flux through the
loop. [4.8 x 10-3 T m2]
2. A small surface area of 10 mm2 inside a uniform magnetic field of strength 0.50 T is
inclined at an angle,  to the direction of the field. Determine the magnetic flux through the
surface if

(a) = 0 [0]
(b) = 30 [2.5 x 10-6 Wb]
(c) = 90 [5.0 x 10-6 Wb]
3. A 400-turn solenoid of length 36.0 cm and radius 3.00 cm carries a current of 5.00 A.
Find
(a) the magnetic field strength inside the coil at its midpoint [6.98 mT]
(b) the magnetic flux through a circular cross-sectional area of the solenoid at its
midpoint. [1.97 x 10-5 Tm2]

4.

Figure 1.0

Three loops of wire move near a long straight wire carrying a current as in Figure 1.0.
What is the direction of the induced current, if any, in (a) loop A, (b) loop B, and (c) loop C.
[0, CCW, CW]

5.

Figure 2.0

The flexible loop in Figure 2.0 has a radius of 12 cm and is in a magnetic field of
strength 0.15 T. The loop is grasped at points A and B and stretched until its area is nearly
zero. If it takes 0.20 s to close the loop, what is the magnitude of the average induced emf in it
during this time? [34 mV]
6.

Figure 3.0

A circular loop of wire of radius 12.0 cm is placed in a magnetic field directed
perpendicular to the plane of the loop, as shown in Figure 3.0. If the field decreases at the
rate of 0.050 0 T/s in some time interval, what is the magnitude of the emf induced in the loop
during this interval? [2.26 mV]

7.

Figure 4.0

Consider the arrangement shown in Figure 4.0. Assume R = 6.00 , l = 1.20 m, and a
uniform 2.50 T magnetic field is directed into the page. At what speed should the bar be
moved to produce a current of 0.500 A in the resistor? [1.00 m/s]

8. In a model AC generator, a 500-turn rectangular coil 8.0 cm by 20 cm rotates at 120
rev/min in a uniform magnetic field of 0.60 T.
(a) What is the maximum emf induced in the coil? [60 V]
(b) What is the instantaneous value of the emf in the coil at t = (/32) s? [57 V]
(c) What is the smallest value of t for which the emf will have its maximum value?
[0.13 s]

9. A solenoid of radius 2.5 cm has 400 turns and a length of 20 cm. Find,
(a) its inductance [2 mH]
(b) the rate at which current must change through it to produce an emf of 75 mV [38
A/s]

10. Two coils, X & Y are magnetically coupled. The emf induced in coil Y is 2.5 V when
the current flowing through coil X changes at the rate of 5.0 A/s. Determine:

(a) the mutual inductance of the coils [0.5 H]

(b) the emf induced in coil X if there is a current flowing through coil Y which

changes at the rate of 1.5 A/s [0.75 V]

11. Primary coil of a cylindrical former with the length of 50 cm and diameter of 3 cm has
1000 turns. If the secondary coil has 50 turns, calculate,

(a) its mutual inductance [8.88 x 10-5 H]

(b) the induced emf in the secondary coil if the current flowing in the primary coil is
changing at the rate of 4.8 A/s. [4.25 x 10-4 V]

12. A motor has coils with a resistance of 30  and operates from a voltage of 240 V.
When the motor is operating at its maximum speed, the back emf is 145 V. Find the current in
the coils,

(a) when the motor is first turned on [8A]

(b) when the motor has reached maximum speed. [3.2 A]

(c) If the current in the motor is 6.0 A at some instant, what is the back emf at that
time? [60 V]

13. (a) If an inductor carrying a 1.70 A current stores energy of 0.300 mJ, what is its
inductance? [0.208 mH]

(b) How much energy does the same inductor store if it carries a 3.0 A current? [0.936
mJ]

14. A 300-turn solenoid has a radius of 5.00 cm and a length of 20.0 cm. Find,

(a) the inductance of the solenoid [4.44 mH]

(b) the energy stored in the solenoid when the current in its windings is 0.500 A.
[0.555 mJ]

15. Considerable scientific work is currently underway to determine whether weak

oscillating magnetic fields such as those found near outdoor electric power lines can affect
human health. One study indicated that a magnetic field of magnitude 1.0 x 10-9 T, oscillating

at 60 Hz, might stimulate red blood cells to become cancerous. If the diameter of a red blood

cell is 8.0 mm, determine the maximum emf that can be generates around the perimeter of
the cell. [1.9 x 10-11 V]

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 6 : GEOMETRICAL OPTICS

Answer all the questions.

TUTORIAL 6.1 : REFLECTION AT A SPERICAL SURFACE

1. During a magic show, an upright image three times the size of a girl is produced by a
spherical concave mirror of radius of curvature 50cm. How far is the girl standing in
front of the mirror?
(16.7cm in front of mirror)

2. (a) An upright image is produced by a spherical mirror at a distance of 30cm from

the center of curvature of this mirror. The magnification is 4.

(i) state the type of spherical mirror used.

(ii) sketch the ray diagram to show how the image is produced.

(iii) calculate the object distance from the mirror and the focal length of the

mirror. (4.5cm, 6.0cm)

(b) can the mirror in (a) be used by a dentist to check the teeth? Explain your

answer.

3. An upright image twice the size of an object is formed by a spherical mirror. If the

distance between the image and the object is 30cm, find the focal length of the mirror

and state what type of spherical mirror it is. (20cm)

4. A concave mirror of a focal length 10cm produces an image twice the size of the

object.

(i) Determine the possible positions of the object. (5cm @15cm)

(ii) Draw ray diagrams to illustrate your answer.

5. An object of height 5.0cm is 30.0cm from a convex mirror of radius of curvature

40.0cm.

(a) Where is the image (-12.0cm)

(b) What is the height of the image. (2cm)

6. A converging spherical mirror of radius of curvature 20.0 cm is used as a shaving

mirror. What is the distance of an object from the mirror if an upright image three

times the height of the object is produced? Draw a ray diagram to illustrate your

answer. (6.67cm)

7. A convex spherical mirror of focal length 50cm is used as a rear mirror of a vehicle.
An object is 200cm behind the rear mirror. Find the position of the image and state its
characteristics. Draw a ray diagram to illustrate your answer.
(-40cm)

8. A concave spherical mirror produced a virtual image two times the height of the
object at a distance of 50 cm from the mirror. What is the focal length of the mirror?
(100cm)

9. A concave spherical mirror has a focal length of 5.0cm. A point object is placed 7.5
cm from the mirror. Determine the position of the image. What are the image
characteristics? Draw a ray diagram to illustrate your answer.
(15cm)

TUTORIAL 6.2 : REFRACTION AT SPHERICAL SURFACES

1. A point object is located 5.0cm from a big block of glass with a spherical concave
surface of radius of curvature 20.0cm. The refractive index of the glass is 1.50. Show
the image is approximately 6.7cm from the concave surface.
(-6.67cm)

2. One end of a glass rod is convex with a radius of curvature 2.5 cm. A point light source
is 6.0 cm from the convex end of the glass rod. Find the position of the image formed
by the refraction of light at the convex glass surface. (Refractive index of glass is 1.50)
(45cm)

3. One end of a long glass rod (n = 1.50) is formed into a convex surface of radius 6.0

cm. An object is positioned in air along the axis of the rod. Find the image position

corresponding to object distances of

(a) 20.0 cm, (45cm)

(b) 3.0 cm from the end of the rod. (-6cm)

4. A goldfish is swimming inside a spherical plastic bowl of water, with an index of
refraction of 1.33. If the fish is 20.0 cm from the wall of the 40.0 cm radius bowl, where
does it appear to an observer outside the bowl?
(9cm inside the wall of the bowl)

5. In a simplified model of the human eye, the aqueous and vitreous humours and the lens

all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose

vertex is 2.60cm from the retina. What should be the radius of curvature of the cornea

such that the image of an object 40.0cm from the cornea's vertex is focused on the

retina? (0.71cm)

6. The radius of curvature of convex surface is 10cm and if an object lies at a distance of
20cm from it in the rarer medium, find the position of the image assuming the refractive
index of the rarer medium is 1.0, while that of the denser medium is 2.0.
(40cm)

7. An object 1.0 cm tall is 1.50 m to the right of a convex spherical surface whose radius

of curvature is 0.50 m. The medium to the right of the surface is air (index of refraction

= 1.0), and the medium to the left has an index of refraction equal to 1.67. Find the

position of the image. Is it real or virtual? (2.5cm)

8. A coin 2.0 cm in diameter is embedded in a solid glass ball of radius 30.0cm show in
the figure below. The index of refraction of the ball is 1.50 and the coin is 20.0 cm from
the surface. Find the position of the image of the coin

TUTORIAL 6.3 : THIN LENS

1. The surfaces of a lens are of radii of curvature 15.0 cm and 10.0 cm. Calculate the

focal length of the lens if the lens is (given the refractive index of lens =1.5)

(a) a converging meniscus (60cm)

(b) a diverging meniscus (-60cm)

2. (a) A double convex lens has faces of radii 18 and 20 cm. When an object is 24 cm

away from the lens, a real image is formed 32 cm from the lens. Determine:

i. The focal length of the lens (13.71cm)

ii. The refractive index of the lens material. (1.69)

(b) A glass lens (n = 1.5) has a focal length of 10.0 cm in air. If it is immersed in a

transparent liquid of refractive index 1.4, what will the focal length be?

(70cm)

3. A biconvex lens is made of glass of refractive index 1.50. The radii of curvature of

the surface are 25.0 cm and 10.0 cm.

(a) What is the focal length of the lens (14.29cm)

(b) What is the focal length of the lens when it is placed in water of refractive index

1.33. (55.8cm)

4. (a) A thin lens of focal length 5.0cm forms an upright image which is twice the height
of the object. Discuss
(i) whether the image is real or virtual
(ii) on which side of the lens the image is relative to the object
(iii) whether the lens is a converging or diverging lens.
(b) draw a ray diagram to determine the object distance and image distance.
(u=2.5cm, v=-5cm)

5. A convex lens of focal length 20.0 cm is used to project the image of a bright object

onto a screen. The height of the image formed on the screen is 50 times the height of

the object. Calculate the distance of the object from lens. How should the object

distance be change so that an image can be formed on a screen placed further away

from lens. (19.6cm)

6. One of the lenses of a student’s spectacles is a diverging meniscus with radii of

curvature 5.0 cm and 8.0 cm. The refractive index of the material of the lens is 1.60.

(i) An object is at distance of 1.0m from lens. Where is the image? (-18.17cm)

(ii) if the student puts on the spectacles when he dives into water of refractive index

1.33, where would the image for the same distance object be formed by lens?

(-39.64cm)

7. An object 25cm away from a lens produces a focused image on a film 15cm away.
What is the focal length of the converging lens?
(9.4cm)

8. If the focal length of the lens in your camera is 2.0cm, at what distance must objects
be placed so that a focused image is produced on a piece of film set 3.0cm from the
lens. (6.0cm)

9. A tree 20.0cm high is located 40.0m from the converging lens of focal length 8.00cm.

(a) calculate the distance from the lens to image (8.02cm)

(b) calculate the magnification (0.00201)

10. A normal human eye has a focal length of about 2.3cm. If you look at the tip of a
pencil, 55.3 cm from your eye, how far is the image from the lens of your eye.
(2.4cm)

11. A converging lens produces an image twice the size of the original.
(a) If the object is placed 40.0cm from the lens, where is the image produced?
(80cm from the lens)

(b) What is the focal length of the lens (26.7cm)

(c) If the image is 6 cm tall, how tall is the original object (3cm)

12. A diverging lens forms an image one-third of the size of an object placed 24cm from
the lens. Find the focal length of the lens.
(12cm)

13. You are given a thin diverging lens. You find that a beam of parallel rays spreads out
after passing through the lens as though all the rays came from a point 20.0 cm from
the centre of the lens. You want to use this lens to form an erect virtual image that is
1/3 the height of the object. Where should the object be placed?

14. A Plano convex lens made up of glass of refractive index 1.5 has a focal length of
25cm. Calculate the radius of curvature of the concave surface.

15. An object is placed at a distance, x, in front of a thin plano-convex lens so that the
image is formed at an equal distance, x, behind the lens is shown in the diagram below

If the refractive index of the lens is 1.5 and the radius of curvature of the curved

surface is 20cm, what is the value of x (80cm)

16. A spider with a diameter of 2.0 cm hangs from the ceiling. The spider and the wall is

200cm. A thin lens is placed so that an image formed on the wall is half the size of the

spider.

(i) State the type of lens used

(ii) Determine the position of the lens from the wall. (66.7cm)

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 7 : PHYSICAL OPTICS

Answer all the questions.

1. a) Explain Huygen’s principle with the aid of a diagram.
b) State the difference between interference and diffraction.

2. A flat observation screen is placed at a distance 1.5 m from a pair of slits. The separation on
the screen between the central bright fringe and the first-order bright fringe is 0.035 m. The
light illuminating the slits has a wavelength of 540 nm. Determine the slit separation. (2.31 x
10-5m)

3. In a Young’s double-slit experiment, the separation, ym between the second-order bright fringe
and the central bright fringe on a flat screen is 0.016 m when the light has a wavelength of 405
nm. Find the separation ym when the light has a wavelength of 560 nm. (0.022 m)

4. Monochromatic light of wavelength 500 nm passes through a double slit produces 50th dark
fringe a point on a screen. What should be the wavelength to produce 36th dark fringe at the
same point? (689 nm)

5. In a double slit experiment where the slit separation is 0.1 mm and the screen is 20 cm away
from the slits. The distance between 5th and 7th bright fringes was observed as 2.56 mm. What
is the wavelength of the light used? (640 nm)

6. Two narrow slits are illuminated by light consisting of two wavelengths 600 nm and unknown.
The second dark fringe of 600 nm light is formed at the same position as the third order bright
fringe of the other light. Determine the unknown wavelength. (300 nm)

7. In a Young’s double slit experiment the screen is placed at 1.6 m from the screen and a
monochromatic light 589 nm was used. If the distance of the 4th bright fringe is 1.6 mm from
the centre, calculate the slit separation. (2.36 mm)

8. With the aid of a diagram, describe the phase change when the light pass through reflective and
non-reflective coating of thin film.

9. Find the thickness of an optical coating MgF2 with refractive index 1.35 in order to eliminate
reflected light of wavelength 550 nm (in air) when incident on a lens of refractive index of 1.50.
(101.85 nm)

10. A mix of red light of ( red = 661 nm) and green light ( green = 551 nm) is directed
perpendicularly onto a soap film of refractive index 1.35 that has an air on either side. What is
the minimum nonzero thickness of the film, so that destructive interference causes it to look red
in the reflected light? (204 nm)

11. Light of wavelength 556 nm is incident perpendicularly on a soap film of refractive index in
air. If the refractive index of soap film is 1.35, what are the two smallest non-zero thickness (in
nm) for which the reflected light undergoes constructive interference? (103 nm, 308 nm)

12. A thin film (refractive index between 1.00 and 1.40) floats on an open tank of oil with refractive
index, n = 1.40. When the light has a wavelength of 642 nm (0n air) shines perpendicularly
down through the air onto the thin film, it looks bright due to interference of reflected light by
the film and oil surfaces. If the thickness of the thin film is 280nm, what is the refractive index
of the thin film? (1.15)

7.3 DOUBLE SLITS & 7.4 THIN FILM

13. A uniform layer of water (n = 1.33) lies on a glass plate (n =1.52), it appears bright when
light of wavelength 432 nm shines perpendicularly on the layer. Determine the minimum
thickness of the film. (162 nm)

14. A soap bubble (n = 1.33) having a wall thickness of 120 nm is floating in air.

a. What is the wavelength of the visible light that is most strongly reflected? (640 nm)

b. Find the two smallest film thickness larger than the one given that can produce strongly
reflected light of this same wavelength. (360 nm; 600 nm)

15. Semiconductors such as silicon are used to fabricate solar cells, devices that generate electric
energy when exposed to sunlight. Solar cells are often coated with a transparent thin film,
such as silicon monoxide (SiO; n= 1.45), to minimize reflective losses. A silicon solar cell (n
=3.50) is coated with a thin film of silicon monoxide for this purpose. Assuming normal
incidence, determine the minimum thickness at the film that will produce the least reflection
at a wavelength of 552 nm. (95.2 nm)

7.5 SINGLE SLIT & 7.6 DIFFRACTION GRATING
1. Explain the formation of single slit pattern by using Huygen’s principle.
2. a) A laser beam of wavelength 625 nm illuminates a single slit width 5.7 x 10-4 m. What is the

angular width of the central maximum? (0.1260 )

b) What will happen to the diffraction patter in a) if the size of the slit is decreased.
3. Light that has a wavelength of 642 nm passes through a slit 4.32 x 10-6 m wide and falls on a

screen that is 1.5 m away. What is the distance on the screen from the centre of the central
bright fringe to the third dark fringe on either side? (66.9 cm)

4. Light with a wavelength of 520 nm (in vacuum) shines through a small slit produces a
diffraction pattern with its central bright fringe 30 mm wide when viewed on a flat screen 0.6
m away from the slit. What is the width of the slit? (2.08 x 10-5 m)

5. A beam of monochromatic light is diffracted by a slit of width 0.600 mm. The diffraction
pattern forms on a wall 1.3 m beyond the slit. The width of the central maximum is 2.00 mm.
Calculate the wavelength of the light. (461 nm)

6. A single slit diffraction pattern is obtained on a screen placed at a distance of 10 cm from the
slit width 5 µm. The wavelength of the monochromatic light used is 5.9 x 10-7 m.

a. Calculate the angular separation between the first and second minima. (6.870 )

b. What is the width of the central bright fringe? (2.38 cm)

c. How many dark fringes are found on the screen? (16)

7. Light of wavelength 587.5 nm illuminates a slit of width 0.75 mm.

a. At what distance from the slit should a screen be placed if the first minimum in the
diffraction pattern is to be 0.85 mm from the central maximum? (1.09m)

b. Calculate the width of the central maximum. (1.7 mm)

8. Light of wavelength 600 nm falls on a 0.40 mm wide slit and forms a diffraction pattern on a
screen 1.5 m away.

a. Find the position of the first dark band on each side of the central maximum. (2.3 mm)

b. Find the width of the central maximum. (4.5 mm)

9. a) Explain briefly the formation of diffraction pattern by a diffraction grating.

b) A monochromatic light of wavelength 5.49 x 10-7 m is incident normally on a diffraction
grating. If a diffraction pattern of the first order is observed at an angle 280 from the normal,
what is the number of lines per mm on the diffraction grating? (855 lines/mm)

10. Monochromatic light of wavelength 600 nm is incident on a diffraction grating which has 7.3
x 105 lines per meter.

a. Calculate the maximum number of orders that can be observed. (n = 2)

b. How to maximize the number of orders?

11. Monochromatic light from a helium-neon laser of wavelength 633 nm is incident normal to
the diffraction grating. If the grating consists of 5000 lines per cm, calculate the angle at which
second order maximum can be observed. (39.30 )

12. White light is spread out into its spectral components by a diffraction grating. If the grating
has 2000 lines per centimeter, at what angle does red light of wavelength 640 nm appear in
the first order spectrum? (7.350 )

13. Light of wavelength 500 nm is incident normally on a diffraction grating. If the third-order
maximum of the diffraction pattern is observed at 32.

a. What is the number of rulings per centimeter for the grating? (2.83 x 10-6 m)

b. Determine the total number of maxima that can be observed in this situation. (11)

14. A diffraction grating that has a 4500 lines per cm produces a second order maximum at an
angle 420 with respect to the central maximum. What is the wavelength of monochromatic
light used? (743 nm)

15. Light containing two different wavelengths passes through a diffraction grating with 1200
slits/cm. On a screen 15.0 cm from the grating, the third-order maximum of the shorter
wavelength falls midway between the central maximum and the first side maximum for the
longer wavelength. If the neighboring maxima of the longer wavelength are 8.44 mm apart on
the screen, what are the wavelengths in the light? (Hint: Use the small angle approximation.)
(78.1 nm and 469 nm)

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 8 : QUANTIZATION OF LIGHT

Answer all the questions.

1. When the intensity of a beam of monochromatic light incident on the cathode of a
photocell is increased, the photoelectric current increases. Which of the following
explains correctly the observation?

A. The photon energy is greater.
B. The amplitude of the incident light wave increases.
C. The kinetic energy of the photoelectrons increases.
D. The rate of photons incident on the cathode increases.

2. When yellow light is incident on a zinc plate, no photoelectrons are emitted. Which of
the following explanation is correct?

A. The stopping potential is higher than the potential of the zinc plate.
B. The intensity of the yellow light is insufficient to eject photoelectrons.
C. The work function on zinc is higher than the energy of the yellow light photon.
D. The wavelength of the yellow light is lower than the threshold wavelength of zinc.

3. The kinetic energy of the photoelectron depends on the following factors except…

A. The type of metal plate.
B. The intensity of the photon.
C. The frequency of the photon.
D. The wavelength of the photon.

4. A photon of sodium light has wavelength of 590 nm. Determine :

a. the speed of the photon.
b. the frequency of the photon. [Answer : f = 5.08x1014 Hz]
c. the energy of the photon in Joule and in eV. [Answer : E = 3.37x10-19 J = 2.11 eV]

5. A sodium lamp of power 100 W emits sodium light of wavelength 590nm. Determine :

a. the total energy produced by the lamp for every 1 second. [Answer : ET = 100 J]
b. the number of photon produced for every 1 second. [Answer : N = 2.97x1020]

6. Cesium has a work function of 1.80 eV. Determine :

a. the minimum energy (in Joule) of photon needed to release an electron from the
metal surface. [Answer : Eo = 2.88x10-19 J]

b. the threshold frequency of cesium. [Answer : fo = 4.34x1014 Hz]
c. the threshold wavelength of cesium. [Answer : o = 6.91x10-7 m]

d. the types of e.m. wave can be used to eject the electron (based on table 1 below).
Justify your answer. [Answer : …]

Table 1 : Range of e.m. wavelength.

Type of e.m. Radio- Micro- Infra- Visible Ultra- X-ray Gamma
waves wave wave red ray
0.3 3.0x10-4 7.0x10-7 light violet 3.0x10-12
Range of 4.0x10-7 3.0x10-9 - < 3.0x10-
wavelength - - -
300 0.3 - - 3.0x10-9 12
(m) 3.0x10-4 7.0x10-7 4.0x10-7

7. In a photoelectric effect experiment, Cesium has a work function of 1.80 eV is used.
The metal is incident by a light of wavelength 590 nm from sodium lamp. Current of
magnitude 0.25 A is detected flows in the circuit. Determine :

a. the maximum kinetic energy possessed by the photoelectrons to move. [Answer :
Kmax = 0.49x10-19 J]

b. the maximum speed of the photoelectrons. [Answer : vmax = 328 kms-1]
c. the number of photoelectron flow in the circuit for every 1 second. [Answer : N =

1.56x1012 ]

8. Refer question 7. The Cesium has area of 1.20 cm2. A voltage is supplied across the
anode (positive pole) and metal which acts as the cathode (negative pole). The voltage
is increased until the current increases to the maximum value of 0.37 A.

a. Determine the maximum number of photoelectron flow in the circuit for every
second. [Answer : N = 2.31x1012]

b. Determine the intensity of sodium light on the metal. [Answer : I = 6.49x10-3 Wm-2]
c. Does the maximum kinetic energy change? Justify your answer. [Answer : … ]

9. Refer question 8. The polarity of the voltage is then overturned. The voltage is
increased until the current reduces to zero.

a. Determine the stopping voltage to stop the photoelectron to reach the anode.
[Answer : Vs = 0.31V]

b. Based on information stated in question 7 and 8, sketch a graph of current, I versus
voltage supplied, V (insert values of Vs, Io and Im)

10. Two identical cesium plates Cs1 and Cs2 are illuminated by sodium lamps of power P1
and P2 respectively. If P2 > P1, sketch graph of current, I versus voltage supplied, V for
both plates on the same graph.

11. Two metal plates M1 and M2 respectively are illuminated by identical sodium lamps. If
the work function of M2 is greater than that of metal M1, sketch graph of current, I
versus voltage supplied, V for both plates on the same graph.

END OF QUESTION

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 9 : WAVE PROPERTIES OF PARTICLE

Answer all the questions.

1. Which of the following objects has the longest de Broglie wavelength?

A. A proton moves at 1x107 ms-1.
B. An electron moves at 1 x107 ms-1.
C. A nitrogen molecule moves at 300 ms-1 (Mass number of nitrogen, A = 14).
D. A bullet of mass 10g moves at 300 ms-1.

2. An electron beam is diffracted by a crystalline solid. Which of the following is the correct
deduction?

A. The electron beam has wave properties.
B. There are centres of positive charge in the crystalline solid.
C. There are empty spaces between atoms in the crystalline solid.
D. X rays are produced when electrons collide with a crystalline solid.

3. An electron is accelerated through a potential difference of 2.0 kV. Determine :

a. the maximum kinetic energy possessed by the electron. [Answer : Kmax = 3.2x10-16 J]
b. the maximum speed of the electron. [Answer : vmax = 2.65x107ms-1]
c. the maximum momentum of the electron. [Answer : p = 2.41x10-23 kgms-1]
d. the minimum de Broglie wavelength of the electron. [Answer : deBroglie = 2.75x10-11 m]

4. A proton is accelerated through a potential difference of 2.0 kV. Determine :

a. the maximum kinetic energy possessed by the proton. [Answer : Kmax = 3.2x10-16 J]
b. the maximum speed of the proton. [Answer : vmax = 6.19x105ms-1]
c. the maximum momentum of the proton. [Answer : p = 1.03x10-21 kgms-1]
d. the minimum de Broglie wavelength of the proton. [Answer : deBroglie = 6.44x10-13 m]

5. An athlete of mass 65 kg is running consistently along 100 m within 9.75 s.

a. Determine the momentum of the athlete. [Answer : p = 666.67 kgms-1]
b. Determine the kinetic energy possessed by the athlete. [Answer : Kmax = 14.11 x106 J]
c. Determine the de Broglie wavelength of the athlete. [Answer : deBroglie = 9.94x10-37m]

Table 1 : Range of e.m. wavelength.

Type of e.m. Radio- Micro- Infra- Visible Ultra- X-ray Gamma
waves wave wave red ray
0.3 3.0x10-4 7.0x10-7 light violet 3.0x10-12
Range of 4.0x10-7 3.0x10-9 - < 3.0x10-
wavelength - - -
300 0.3 - - 3.0x10-9 12
(m) 3.0x10-4 7.0x10-7 4.0x10-7

END OF QUESTION

KOLEJ MATRIKULASI KEJURUTERAAN JOHOR
EP025 PHYSICS 2

TUTORIAL 10 : NUCLEAR & PARTICLE PHYSICS

10.1: Binding Energy and Mass Defect

1. How many protons are there in a nucleus of the isotope of Rubidium, 8375
A. 85
B. 122
C. 37
D. 48

2. Which isotope below has the highest nuclear binding energy per gram? No calculation
is necessary.
A. 4He
B. 16O
C. 32S
D. 55Mn

3. Which of the following statements is incorrect?
A. Mass defect is the amount of matter that would be converted into energy if a
nucleus were formed from initially separated protons and neutrons.
B. Nuclear binding energy is the energy released in the formation of an atom from
subatomic particles.
C. Nuclei with highest binding energies are the most stable nuclei.
D. Einstein postulated the Theory of Relativity in which he stated that matter and
energy are equivalent.
E. Mass number is the sum of all protons and electrons in an atom.

4. FIGURE 1 shows the identity of sodium (natrium) atom based on the periodic table.

11
Na
22.98977

FIGURE 1

Determine
a. the number of proton and electron of sodium atom.
b. the number of nucleons of sodium atom.
c. the number of neutrons of sodium atom.
d. the charge of sodium nucleus
(a) 11;11, b) 23, c) 12, d) +1.76x10-18 C)

5. Based on question 4, determine

a. the total mass of proton of sodium atom (in kg and u).

b. the total mass of neutron of sodium atom (in kg and u).

c. the total mass of electron of sodium atom (in kg and u).
(a) 1.8399x10-26 kg; 11.0800 u, b) 2.0099x10-26 kg; 12.1040 u, c) 1.0020x10-29 kg;
6.0344x10-3 u)

6. Based on question 4 and question 5, determine:
a. the mass defect of sodium nucleus (in kg and u).
b. the binding energy of sodium nucleus (in Joule and eV).
c. the average binding energy (binding energy per nucleon) of sodium nucleus
(in Joule and eV).
(a) 3.3254x10-28 kg; 0.2003 u, b) 2.9929x10-11 J; 186.541MeV, c)
1.3013x10-12 J; 8.1105MeV)
(b)

7. FIGURE 2 shows the identity of uranium atom based on periodic table.

92
U
238.0289

FIGURE 2
Determine:
a. the number of proton and electron of uranium atom.
b. the number of nucleons of uranium atom.
c. the number of neutrons of uranium atom.

(a) 92;92, b)238, c)146)

8. Based on question 9, determine :
a. the total mass of uranium nucleon (in kg and u).
b. the mass defect of uranium nucleus (in kg and u).
c. the binding energy of uranium nucleus (in Joule and eV).
d. the average binding energy (binding energy per nucleon) of uranium nucleus (in
Joule and eV).
(a) 3.9517x10-25 kg; 237.9784 u b) 3.2482x10-27 kg; 1.9561 u c) 2.9234x10-10 J;
1822.095 MeV d) 1.2283x10-12 J; 7.66MeV)

9. By comparing the binding energy and the average binding energy between sodium and
uranium, which nucleus is more stable? Justify your answer. (Sketch binding energy
per nucleon against nucleon graph and mark the position)

10.2 Radioactivity

1. Which of the following is incorrect about an alpha particle?
A. It is a helium nucleus.
B. It has high penetrating power.
C. It has twice magnitude of electron’s charge.
D. It is deflected by electric and magnetic fields.

2. The half-life of particle is 64 hours. What fraction of it will remain undecayed after 8
hours?
A. 0.50
B. 0.79
C. 0.92
D. 0.95

3. The half-life of a radioactive material is 67 seconds. How long after the start will the
fraction of undecayed atoms remaining be 1/3 of the initial number?
A. 86 s
B. 96 s
C. 106 s
D. 116 s

4. Thorium-234 has a half-life of 24 days. The initial activity of a sample of thorium-234
is 8.0 ×104 Bq.

a) Calculate the activity of the sample after 72 days?
b) How long does the sample take for its activity to become 3.0 × 104Bq?

5. Radium-266 is found to have a decay constant of 1.36 × 10-11 Bq. Given that Curies
had roughly 200g of radium in1898.Determine its,
c) half-life in years
d) mass remain 100 years later

6. The radioactive isotope 198 Au has a half-life of 64.8 hours. A sample containing this
isotope has an initial activity (t = 0) of 40.0 μCi. Calculate the number of nuclei that

decay in the time interval between t1= 10.0 hours and t2 = 12.0 hours.
(1μCi = 3.7×104 decay/s)

7. A sample of radioactive isotope I131 is used for medical diagnosis of the kidneys. The

53

isotope has a half-life of 8.0 days and the sample is required to have an activity of 8.0

× 105 s-1 at the time it is given to the patient. Calculate the mass of the I -131 present in

the sample

i. at the time it is given

ii. when it is prepared 24 hours earlier

iii. 24 hours after being given

Suggested Answers :

4. a) 1.0 x 104 Bq

b) 34.1 days

5. a) 1.62 x 103 y

b) 192 g

6. 9.47 x 109 nuclei

7. b) i. 1.74 x 10-10 g

ii. 1.9 x 10-10 g

iii. 1.6 x 10-10 g

END OF QUESTIONS

GOOD LUCK IN YOUR PSPM II EXAMINATION