Name:Class: Date:

SMK (L) Methodist Kuala Lumpur

STPM Physics Semester 2

Revision2

1

Consider three point charges at the corners of a triangle, as shown in the diagram below.

Given q1 = 6.00 10-9 C, q2 = - 2.00 10-9 C, q3 = 5.00 10-9 C, and the distances of separations are shown in the diagram. Find the magnitude of the resultant force on q3. [6 marks]

2

The diagram below shows a circuit consisting two resistors and two cells of negligible internal resistance. The values of e.m.f and resistance are as shown

Calculate the power dissipated in the circuit.[4marks]

3

(a) What is meant by eddy current?[2marks]

(b) A circuit consists of a coil, a lamp and an a.c. source as shown below.

A solid iron core is introduced into the coil, explain

i. why the lamp is dimmer after the core has been introduced, [3marks]

ii. why the core becomes hot. [3marks]

(c) A coil with 200 turns of wire is wrapped on a square frame, 18.0 cm on a side. Eachturn has the same

area, equal to that of the frame, and the total resistance of the coil is2.0 . A uniform magnetic field is

applied perpendicularly to the plane of the coil. Ifthe field changes uniformly from 0 to 0.500 T in

0.8.00s, determine

i. the change in flux through the coil during the 0.80-s interval.[3 marks]

ii. the magnitude of the induced emf in the coil while the field is changed. [2 marks]

iii. the magnitude of the induced current in the coil while the field is changing.[2 marks]

4

The figure below shows a proton moves with velocity v and enters perpendicularly into a uniform magnetic field B.

(a) Describe the path of the motion of the proton. [1 mark]

(b) i. In the figure above, draw the direction of the electric field strength E required so that the proton

continues to move without deflection. [1 mark]

ii. Derive an expression for the magnitude of the electric field strength E required. [2 marks]

iii. A deuterium ion with velocity v which is equal to the velocity of proton in (a) above, enters the same

arrangement of B and E. Explain the subsequent path of the deuterium ion. [1 mark]

5

(a) State Kirchhoffs laws. Explain how each is based on a fundamental physical principle. [4marks]

(b) Use the laws to deduce values of the currents Ia, Ib, Ic and Id as shown in the circuits below. [8marks]

(c) Two resistors having resistances of 1.8 k and 4.7 k are connected in series with a battery of emf 12

V and negligible internal resistance as shown in the diagram.

Calculate the potential difference across each of the resistors. [3marks]

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