Physics - Trial Semester 2 MS

Marking Scheme Trial Sem 2 STPM 2021

Question Answer Mark Total
1A SECTION A 1

2A 1

3C 1
4c 1
5A 1

6D 1

Marking Scheme Trial Sem 2 STPM 2021 1
7D 1
8A 1
9B 1
10 A
1
11 C 1
12 A 1
13 B 1
14 C

Marking Scheme Trial Sem 2 STPM 2021 1 15
15 C

SECTION B

16 (a) 1
16 (b)(i) 3
16(b)(ii)
1

1
1

2
1

1
3

1

1

Marking Scheme Trial Sem 2 STPM 2021 22
17(a)
17 (b) 22

17(c) SECTION C 3
18 (a) 2
1
18 (b) (i)
18 (b) (ii) 33
18 (b)(iii)
1
3

1
1
12
1
12
1

Marking Scheme Trial Sem 2 STPM 2021 22
18 (b)(iv) 33

18 (c)

19 (a) emf of a battery is the quantity of electrical energy supplied by 2 2
19 (b) the battery to every unit charge that passes through the 2
battery, whereas p.d between two points is the work done per
19 (c) (i) unit charge. 2
19 (c)(ii) Kirchoff’s first law states that in an electric circuit, the total 2
19 (c)(iii) 2
19 (d)(i) current entering a junction is equal to the total current 2 3
leaving the junction.
d(ii) 3
Kirchoff’s second law states that the algebraic sum of the

changes in electric potential around a closed loop in a

circuit is equal to zero.

1.25 = I + 0.5 1
I = 0.75 A 1

ε1 – 0.75 x 16 = 0 1

ε1 = 12 V 1
ε2 + 0.5 x 5 – 0.75 x 16 = 0 1

ε2 = 9.5 V 1
1
Assume that the driver cell has zero resistance, therefore 1

VAB = 4.0 V 1

ε = 35  4.0 = 1.4 V
100

Reason: The driver cell may have an internal resistance .
When VAC = 1.18 V; AC = 30.2 cm

Marking Scheme Trial Sem 2 STPM 2021

Refer to the potentiometer: 1.18 = 30.2 VAB 2
100 1

VAB = 3.907 V

Therefore, ε = 35  3.907 = 1.37 V
100

20 (a) (a) The charged particle is moving parallel to the magnetic 3 3
field. Hence, no magnetic force is acting on the particle.

20 (b)(i)

F = qvB = mv2 2
r 4

r = mv 1
qB
1
r = 2.38 x 10-2 m

20 (b)(ii) Momentum = mv
20 (c)(i)
v = 1.52 10 −23 12
1.67 10 −27 1
12
= 9.10 103 ms−1
1
B = µonI

= (4π x 10 -7)( 25 )(5 x 10 -3)
0.01
= 1.57 x 10 -5 T

20 (c)(ii) F = Bev = (1.57 x 10 -5)(1.6 x 10 -19)(1.5 x 105) 12
20 (c)(iii) = 3.77 x 10 -19 N
1
The displacement of the electron is perpendicular to the 22

centripetal force.
Hence, no work is done.