A+ BLOG-SSLC-PHYSICS REVISION NOTES [ENGLISH MEDIUM]-questions

Physics – Questions

Lesson 1

1.What are the devices that give heating effect of electric current
Electric Iron electric stove, Immersion Heater, Electric kettle, soldering Iron
*Mathematical equations for finding heat while flowing current through a conducter
H=I2RT, H=VIT, H=V2t/R
2.What is safety fuse?
Safety fuse is device which protects us and the appliances from danger when excess current flows
through the circuit. It works on the heating effect of electric current. It has low melting point
* The main part of safety fuse : Fuse wire : In circuit it is connected in series
3.Which are the circumstances that cause high electric current, leading to the melting of fuse wire?
Short circuit, over loading
4.Mathematical equations for finding electric power
P=I2R, P=V2/R, P=VI
5.Why is the bulb filled with inert gas or nitrogen
To reduce vaporisation
6.What are the properties tungsten filament
High resistivity, high melting point, high ductility, ability to emit white light
7.Nichrome is not used as filament in incandescent lamps Why?
It can’t be drawn into thin wires, it cannot emit light
8.What are the advantages of discharge lamps?
No energy loss in the form of heat, Greater longevity, Low power consumption, discharge lamp
gives out more light energy
9.What are the advantages of LED Bulb?
There is no loss of energy in the form of heat, Since there is no mercury in it, it is not harmful to
environment, Low energy consumption, Greater longevity, Greater efficiency
10.State Joules Law
The heat generated in a current carrying conductor is directly proportional to the product of the
square of the current in the conductor, the resistance of the conductor and the time of flow of
current.
Lesson 2
1.Difference between permanent magnet and electromagnet

Bar magnet Electromagnet

The magnetism is permanent The magnetism is temporary

Polarity is unchanged Polarity can change

Cannot change the magnetic strength Magnetic strength can change

2.What is solenoid?
Solenoid is a conducting coil wound in the shape of a spring
3.What are the factors affecting the strength of the magnetic field of a solenoid carrying current
Intensity of current, Number of turns, Area of cross section of soft iron core
4.What is the relationship between direction of current and poles of solenoid?
The end of the solenoid at which current flows in the clock wise direction will be the South Pole
and the end at which current flows in the anticlockwise direction will be the North Pole
5.What are the factors that influence the direction of motion of the conductor?
Direction of current , Direction of magnetic field
6.Which is the rule that will help to find out the direction motion of the conductor while flowing
current?
Fleming’s Left Hand Rule

7.Which are the parts of an electric motor?
Magnet, Armature, Graphite Brushes, Split rings
8.What are the principles behind the working of electric motor?
Motor Principle, Fleming’s Left Hand Rule
9.What is the energy conversion in a Motor?
Electrical energy is converted into Mechanical Energy
*In Loud Speaker -Electrical Energy is converted to Mechanical Energy(Sound Energy)
* The working principle of Loudspeaker : Motor Principle
10.what is the function of split rings in an electric motor?
Change the direction of the current
11.State Right Hand Thumb Rule of James Clark Maxwell
Imagine you are holding a current carrying conductor with the right hand in such a way that the
thumb points in the direction of the current. The direction in which the other fingers encircle the
conductor gives the direction of the magnetic field.
The same rule is Right Hand Screw rule.
*If a right hand screw is rotated in such a way that its tip advances along the direction of the current
in the conductor, then the direction of rotation of the screw gives the direction of the magnetic field
around the conductor
12.State Fleming’s Left Hand Rule
Hold the forefinger, the middle finger and the thumb of the left hand in mutually perpendicular
directions. If the forefinger indicates the direction of the magnetic field and the middle finger, the
direction of the current, then the thumb will indicates the direction of motion of the conducto
Lesson 3
1.What is electro magnetic Induction?
Whenever there is a change in the magnetic flux linked with the coil, electricity is induced in the
coil. This phenomenon is electromagnetic induction
*The current induced is the induced current, *The voltage induced is the induced emf
2.What are the factors affecting the induced current?
Number turns of the coil, Strength of the magnet, Speed of the magnet or solenoid
3.what is meant by direct current(DC)
Current flows only in one direction
4.What is alternating current(AC)
If the direction of current changes at regular intervals of time. It is an alternating current
5.What is Generator?
Generator is a device that make use of electromagnetic induction. It converts mechanical energy
into electrical energy
6.Which are the parts of an AC generator
Armature, Brushes, Slip rings, Field Magnet
7.What is the frequency of AC
The number of cycles per second is the frequency of AC
8. How much is the frequency of AC used for distribution in India? 50 Hz
9.When 50 Hz Ac is used, how many times will the direction of current change ? :100
10.In AC generator Which part is kept stationary. Why?
Armature is kept stationary and field magnet is allowed to rotate. The Armature is too heavy to
rotate. This helps to eliminate the graphite brushes
11.Which are the parts of a DC Generator?
Field magnet, Armature, Brushes, Split rings
12.What are the similarities between DC motor and a DC Generator?
Both have permanent magnet, Armature, Split ring commutator, Brushes
13.What is period?
The time taken by the armature coil for a full rotation is called the period, T. Time taken for half
rotation (180º) is T/2

14.What is mutual induction?
Consider two coils of wire kept side by side. When the strength or direction of the current in one
coil changes, the magnetic flux around it changes. As a result, an emf is induced in the secondary
coil. This phenomenon is the mutual Induction.
*The coil into which we give current for the production of magnetic field is the primary coil and the
coil in which induced emf generated is the secondary coil
15.Which is the device based on the principle of mutual induction?
Transformer
Comparison between step up transformer and step down transformer

Step up transformer Step down transformer

Number of turns in the secondary coil is greater Number of turns in the secondary coil is less

than that of primary coil than that of primary coil

Thick wires are used in the primary and thin Thin wires are used in the primary coil and thick
wires in the secondary wire is used in the secondary coil

*Equation connecting number of turns and voltage: Vs/Vp= Ns/Np
*Equation connecting voltage and current : Ip/Is=Vs/Vp
*equation for finding power: P=VI
*In Transformer power in the primary=power in the secondary
16..What is self induction?
The change in the magnetic flux due to the flow of an AC (current) in a solenoid will generate a
back emf in the same solenoid in a direction opposite to that applied to it This phenomenon is
known as the self induction.
*An inductor is is an insulated copper wire wound in a helical shape. They reduce the current in a
circuit
17.Inductors are used in AC circuits. What is the reason?
To regulate current without loss of power.
*Resistors cannot be used instead of inductors because energy (current) wasted in the form of heat
18.Inductors are not used in DC circuits Why?
There is no change in magnetic field and no induced emf forms. So no back emf. No self Induction
occurs
19.Parts of moving coil microphone
Voice coil, diaphragm, Permanent magnet
20.Working principle of Moving coil microphone
Electromagnetic Induction
21.What is the energy transformation in a moving coil microphone?
Mechanical energy is converted into electrical energy
*Working of moving coil microphone
The voice coil is situated in a magnetic field. The diaphragm connected to the voice coil vibrates in
accordance with the sound waves falling on it. As a result, electricals signals corresponding to the
sound waves are generated i the voice coil.
22.Which are the devices worked on the principle of electromagnetic induction?
Generator, moving coil microphone, transformer(mutual induction)
23.What are power stations?
Power stations are places where electricity is generated in large scale. Three phase AC generators
are used in power stations.
24.At what voltage current is produced in power stations?: 11KV(11000V)
25.What is the voltage for household purposes? :230V
26.What is the voltage needed for industrial purposes?: 400V
27.What is the method to reduce the transmission loss?
Transmission of current at high voltage

28.Which type of transformer is there in power station? : Step up transformer
29.Which type of transformer is distribution transformer?: Step down transformer
30.What is the potential of neutral line? : Zero
*The potential difference between a phase and a neutral is 230V
*The potential difference between any two phase is 400V
31.To which device the electric line reaching home connected first
Kilowatt hour meter. (Watt hour meter)It is used to measure the electrical energy consumed.
Unit of electrical energy-Kilowatt hour
32.In which lines are the fuses connected?: Phase line
*Main Switch: It is used to switch off the electric supply. It is connected in between fuse and ELCB
*In wiring red colour is used for phase line, black for neutral, green for earth.
*In three pin socket earth wire is connected to the larger pin.
33.How are the household devices connected ?: Parallel
34.What are the advantages of connecting devices in parallel
Devices work according to the marked power, Devices can be controlled using switches,
Effective resistance is low, All devices get equal voltage
35.What is MCB?
It is used instead of fuse wire. It automatically breaks the circuit if excess flow of current in circuit.
36.What is ELCB? :It helps to break the circuit when there is current leak
*In three pin plug ,earth pin is connected to the body of the device
*First Aids for electric shock: Raise the temperature of the body by massaging, Give artificial
respiration, Start first aid for the heart, Take the person to the hospital
Lesson 4
1.What are Laws of Reflection
*The incident ray, reflected ray and normal to the surface are in the same plane
*Angle of incidence is equal to angle of reflection
2.What is regular reflection?
The light rays falling on smooth surface, reflects in a regular manner. Reflected rays are travelling
in parallel, This phenomenon is known as regular reflection. Images are formed
3.What is Irregular reflection(scattered reflection)?
Light rays falls on rough surface ,undergoes an irregular reflection.
Reflected rays are not travelling in parallel, No image formation
4.What is scattering?
In the dust particles of the atmosphere, light undergoes scattered reflection. This is scattering.
5.What is the relation between the angle of between the plane mirrors and the number of images?
Number of images, n=360/θ-1
As the angle between the mirrors decreases number of images increases
6. Relationship between magnification and size of the image
a. When magnification is less than 1,the size of the image is smaller than the size of the object
b. When magnification is 1 the size of the image and size of the object are equal
c. When magnification is more than 1, the size of the image is greater than the size of the
object
d. Magnification of real image is -ve
e. Magnification of virtual image is +ve
7.Which mirror has maximum field view? :Convex mirror
*So Convex Mirror are used as rear view mirrors in motor vehicles
8.What is mirror equation?
1 /f=1/u +1/v, u=Distance between object and mirror, v=Distance between image and mirror
f=focal length
*f=uv/u+v
*u=fv/v-f
*v=fu/u-f

PLANE MIRROR CONVEX MIRROR CONCAVE MIRROR

Position of Position of image and
object features

Image is behind the Image is formed in At infinity At F
real
mirror. Distance of between the pole inverted
diminished
object from the mirror and (mirror)
Real
distance of the image from and the principal focus. inverted
diminished
the mirror are equal. The image is Beyond C
The image is virtual diminished Real
inverted
the image is erect virtual Same size

Image is same size as that erect
USE: USED AS REAR At C
of the object

USE: FOR OBSERVING VIEW MIRROR

THE FACE

Between C and Beyond C
F Real

inverted
magnified

At F At infinity
reflected rays are parallel

Between F and Behind the mirror
P virtual

erect
magnified

USES OF CONCAVE MIRROR USES
POSITION OF IMAGE AND FEATURES

Converge distant rays to the principal focus Solar concentrators, Solar furnaces, ENT doctors
used as head mirror

Reflects the rays coming from principal focus as Search light, head light of vehicles
parallel rays

For the object placed in between principal focus Torches, Search lights, Shaving mirror, dentists
and pole ,the images formed are enlarged and mirror
erect

9.The mirrors used in following situations and reason for the use
A. Solar furnace-Concave mirror: Converges heat rays at a point
B. Solar cooker: Concave mirror: Converges heat rays at a point
C. Rear view mirror: forms virtual, erect and diminished image. Its field view is maximum
D. For getting an image of tall building: Convex mirror: Gives virtual, erect and diminished image.
Its field view is maximum
Lesson 5.
1.What is refraction?
When a ray of light entering obliquely from one transparent medium to another, its path undergoes a
deviation at the surface of separation. This is refraction
*As the optical density of a medium increases the speed of light decreases

3.Following are the media arranged in increasing order of optical densities
Air<Water<Glass<Diamond
* While entering from air to glass (from a medium of lower optical density to that of greater one)
the refracted ray deviates toward the normal
*While entering from glass to air (from a medium of greater optical density to that of lower one)
the refracted ray deviates away from the normal
4.What is angle of incidence?
The angle between the incident ray and the normal is called the angle of incidence
5.What is angle of refraction?: The angle between the normal and the refracted ray
*The ray of light entering from medium to the other undergoes deviation at the plane of separation
of the two media
7.Does refraction take place for a ray while entering a medium normal to it? :No
8.Laws of Refraction
The angle of incidence, the angle refraction and the normal at the point of incidence on the surface
of separation of the two media will always be in the same plane
the ratio of the sine of the angle of incidence to the sine of the angle of refraction will always be a
constant. This is known as Snell’s Law
The constant from Snell’s Law is known as Refractive Index .This is indicated the by the letter n
9.What is relative refractive index?
The refractive index of a medium with respect to another is called relative refractive index
10.What is absolute refractive index?
The refractive index of a medium with respect to vacuum is called absolute refractive index
11.Equation for finding absolute refractive index of a medium
Speed of light in air/speed of light in the medium = C/V
12.What is critical angle?
When a ray of light passes from a medium of greater optical density to that of lower optical density,
the angle of incidence at which the angle of refraction becomes 90° is the critical angle..The critical
*critical angle of glass=42°
*The critical angle of water=48.6°
13.What is Total internal Reflection
When a ray of light passes from a medium of higher optical density to a medium of lower optical
density at an angle of incidence greater than the critical angle, the ray is reflected back to the same
medium without undergoing refraction. This phenomenon is known as total internal reflection
14..Examples of refraction
*Sun can be seen in the horizon just before sun rise and just after sunset, The bottom of a pond is
seen raised, Feeling of mirage
15.Examples of total internal reflection
*The bottom of the aquarium is seen reflected on the surface of water,
Medical field------- Endoscope, Telecommunication--- Optical fibre cables
16.What is lens?
A lens is a transparent medium having spherical surfaces.
17.What is optic centre: It is the midpoint of a lens(P)
*Centre of Curvature(C)
Centre of curvature is the centre of the imaginary spheres of which the sides of the lenses are parts
*Principal Axis
It is the imaginary line that passes through the optic centre joining the two centre of curvatures
*Principal Focus: The converging point of refracted rays is the principal focus
Convex lens and concave lens has 2 focus (focii)
*Focal length: Distance from optic centre to principal focus(f)
18.What is the nature of image formed by a concave lens?
*Position of the image: Same side of the object in between F and P,
* features :Virtual, erect, diminished

Features of Image formation using convex lens

POSITION OF OBJECT POSITION OF IMAGE NATURE OF IMAGE

Real/ Inverted/ Magnified/
Virtual
erect diminished/

same size

At infinity At F Real Inverted Diminished
beyond 2F Between F And 2F Real Inverted Diminished
At 2F At 2F Real Inverted Same Size
Between 2F and F Beyond 2F Real Inverted Magnified
At F Infinity Real Inverted Very large
Size
Between F and lens Same side of the object Virtual Erect Magnified

19.What is lens Equation? :1/f=1/v-1/u
20.What is magnification?
Magnification is the ratio of the height of the image to the height of the object. It shows how many
times the image is larger than the object.
Magnification=Height of the image/Height of the objectc ie. hi/ho, Magnification=v/u
Uses of lens
In telescope, In spectacles, In camera, In magnifying glass, reading lens, microscope, projector,
binocular
Power of a lens: p=1/f
Unit of power=dioptre(D)
power of convex lens= +ve
power of concave lens=-ve
21.What is the relationship between optical density and temperature?
As temperature increases ,optical density increases
Lesson 6
1.What is near point?
Near point is the nearest point at which the objects can be seen distinctly. The near point is 25cm
2.What is far point?
Far point is the farthest point at which the objects can be seen distinctly. It is infinity
3.What is Power of Accommodation?
The ability of the eye to form an image on the retina by adjusting the focal length of the lens in the
eye, by varying the curvature of the lens, irrespective of the position of the object, is the power of
accommodation
4.What is Hypermetropia?
Since the image is not formed on the retina, instead of being formed at the retina, nearer objects
cannot be seen clearly event though distant objects are clearly seen. This defect of the eye is the
long sightedness.
The near point of the eye of such a person will be at a distance of more than 25cm
5.What is the reason for Hypermetropia?: *The size of the eye ball is smaller
*The focal length of the eye lens is high ( power low)

6.What is the remedy for the long-sightedness?: By using a convex lens
7.What is Myopia or Near-sightedness?
For some persons nearby objects can be seen clearly, but they cannot see distant objects clearly.
Reason
*The size of the eyeball is smaller
*Focal length of the eye lens is low(power high)
8.What is presbyopia?
For elderly people the distance to the near point is greater than 25cm. This is due to diminishing
ability of ciliary muscles. For such persons power of accommodation will be less.
Remedy:*By using convex lens
9.What is composite light?
Light that is composed of more than one colour : example: White light
10.What is dispersion?
Dispersion is the phenomenon of splitting up of a composite light into its constituent colours.
*Spectrum: The regular array of colours formed by dispersion is the visible spectrum.
11.Which colour deviates the most due to dispersion? : Violet. Reason: wavelength less
12.Which colour deviates less? : Red :Reason Wavelength more
13.When is the rainbow formed?
Rainbow is formed at rainy season in the morning and evening
14.Where will be the sun When the rainbow is in the east? : West
15.Where will be the sun when the rainbow is seen in the west? :East
16.What is the reason for the formation of rainbow? : Dispersion
17.How many times does a ray of light undergo refraction when it passes through a water droplet?
2 times
18.How many times does a ray of light undergo Total internal reflection? : 1 time
19.What is the colour seen at the upper edge of the rainbow? :Red
20.What is the colour seen at the lower edge?: Violet
21.What is persistence of vision?
When an object is viewed by a person, its image remains in the retina of the eye for a time interval
of 0.0625s(1/16s) after seeing it. This phenomenon is called persistence of vision.
*If more than one scene is viewed within 0.0625s, the effect of all these scenes will be felt by the
eye simultaneously.
22.What is scattering ?
Scattering is the change in direction brought out by the irregular and partial reflection of light when
it hits the particles of the medium
Observations of the experiment using Sodium Thiosulphate and Hydrochloric acid for
proving Scattering
*When hydrochloric acid is added to the sodium thiosulphate solution Which colour spread first?
Blue
*The order of colours emerging from the solution is VIBGYOR
*Which is the final colour ? : Red
*At last the Ash colour emerges
23.What is is the relationship between size of particle and scattering?
As the size of particle increases ,the rate of scattering also increases
24.Which colour undergoes maximum scattering? :Violet
25.Which colour undergoes least scattering? : Red
26.What is Tyndal effect?
When rays of light pass through a colloidal fluid or suspension, the tiny particles get illuminated
due to scattering. Because of this ,the path is made visible. This phenomenon is Tyndal effect.
27.Which is the association deals with the task of reducing light pollution?
International Dark Sky Association

28.When Newton’s Disk rotates fast it appears white What is the reason behind it?
Persistence of Vision
Lesson 7
1.What is combustion?
The burning of fuels with the help of oxygen
2.Which are the products of combustion? : Carbon dioxide, steam, heat and light
3.Why is smoke test done in vehicles?
For knowing carbon monoxide and hydrocarbon content present in smoke
4.How is fossil fuels formed?
Fossil fuels are formed by the transformation of plants and animals that went under the earth’s crust
millions of years ago. They are not renewed
5.Which is the main component of coal? :Carbon
6.Which are the classifications coal of according to carbon content?
Peat, lignite, anthracite and bituminous coal
7.Which are the substances obtained when coal is distilled in the absence of air?
Ammonia, coal gas, coal tar and coke
LNG: Liquefied Natural Gas
CNG: Compressed Natural Gas
LPG: Liquefied Petroleum Gas
8.Which are the main components of LNG and CNG? :Methane
9.Which is the main component of LPG? :Butane
10.Which is the substance added to know the LPG leak? :Ethyl Mercaptan
11.How can we know the expiry date of cooking gas(LPG)
This is marked on the top of the cylinder. If it is marked “A24”,the A indicates the months from
January to March, 24 indicates the year 2024.This cylinder has maturity period upto March 2024.
If it is recorded as B, then it is from April to June, C denotes July to September, and D denotes
October to to December
*LPG is denser than air
12.What is BLEVE?
When LPG becomes gas, the container cannot accommodate the entire gas. This increases the
pressure to a very high level causing a huge explosion. This is known as BLEVE (Boiling Liquid
Expanding Vapour Explosion)
13.What is Biomass?The body of parts of animals and plants are known as Biomass. It is renewable
14.Which gases are the cause of foul smell from Bio_wastes? : H2S, methane
15.How is Biogas formed?
When bio-waste is deposited in a biogas plant in the absence of oxygen, Biogas is formed by the
action of bacteria.
16. Which are the main constituents of Biogas? : Methane and carbon dioxide
17.What is the weight of LPG filled in the cylinders? : 14.2kg
18.What is Calorific value?
The amount of heat liberated by the complete combustion of 1kg of fuel.
Its unit is kilojoule/kilogram
19.Which the most efficient fuel based on calorific value? :Hydrogen
20.Which are the instances when hydrogen is used as fuel? :Hydrogen In rockets
21.Why is hydrogen not used as a domestic fuel?
Hydrogen is highly is highly inflammable and explosive. It is difficult to store and transport.
22.The energy change in hydroelectric power stations
Potential Energy----->Kinetic Energy-------->Mechanical Energy------->Electrical Energy
23. The energy change in Thermal Power Stations
Chemical Energy------>Heat Energy------------>Mechanical Energy---------->Electrical Energy
24.What is the energy transformation take place in a solar panel?
Light Energy is converted into electrical energy

*solar panel cannot use during night and when sky is cloudy
25.What is photovoltaic effect?
When solar energy falls on N side of a solar cell, a small electric current is obtained due to the flow
of electrons to P region from N region. This phenomenon is photovoltaic effect
* Parts of Solar Cooker
A box with blackened interior, A glass cover for the box, A mirror outside the box
26.What is the use of Concave reflectors in Solar Thermal Power Power Plant?
Used to focus the Sun’s rays on the blackened pipes filled with water
*Tidal energy cannot be used in Kerala since the rise in water due to high tide is less than 1 m
27.What are the limitations of wind mills?
Wind is available most time of the year, Require storage systems to use electricity when there is no
wind, About 2 hectares of land is needed for the production of 1 megawatt power, the expense to
establish a wind mill is very high, expense for repairing is also high.
28.What is hot spot?
Earth’s interior is in molten state. Magma, which is at a higher temperature ,comes out of the core
through its softer regions. Such places are called hot spots
*There is no hotspot in Kerala ,so geothermal power plants are not possible in Kerala
29.What is nuclear fission?
Nuclear fission is the process by which the nuclei of greater mass split into lighter nuclei, using
neutrons
30.What is Nuclear Fusion?
Nuclear fusion is the process in which lighter nuclei are combined to form heavier ones.
31.What is the principle behind the Atom Bomb? : Nuclear Fission
32.What is the principle behind Hydrogen Bomb? : Nuclear Fusion
33.What are Nuclear Power Stations?
Power Stations that make use of controlled nuclear fission for producing electricity
34.What is Nucleus Reactor?
System that converts nuclear energy into electrical energy
Energy change= Nuclear energy---->Heat Energy------>Mechanical Energy----->Electrical Energy
35.What is Nuclear Pollution?
The Pollution caused by radio active substances and radiations in water, air and environmen
Sources that gives Green energy and Brown Energy

Green Energy Brown Energy

Solar cells Atomic reactors
Tidal Energy Diesel Engines
Hydro electric power Thermal power stations
Wind mills

Sources comes under Renewable sources of energy and Non renewable sources of energy

Renewable Sources Non Renewable Sources

Sun light Petroleum
Wind Coal
Rain Natural gases
high tide nuclear energy