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May/June-2005

26 The diagram shows a positively charged acetate strip and a negatively chargedpolythene stripthat are freely suspended.

 Two rods X and Y are brought up in turn to these two strips. Rod X attracts theacetate strip butrepels the polythene strip. Rod Y does not repel either the acetate strip or thepolythene strip.Which type of charge is on each rod?

2 ! cell is connected to a resistor.What is the e.m.f. of the cell e"ual to?! The potential di#erence across the resistor for each unit of current.$ The power produced in the circuit for each unit of charge that passes.% The wor& done in the circuit for each unit of charge that passes.' The wor& done in the circuit for each unit of current.

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2( ! cell is connected in series with an ammeter and a lamp. The current is ) !.

*n which circuit+ using identical cells+ lamps and ammeters+ is the current reading 2

!?

2, Which circuit contains a cell+ a light-emitting diode and a /ed resistor?

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01 *n each of the circuits below+ a short circuit occurs.*n which circuit would the fuse blow and ma&e the circuit safe to repair?

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06 The diagram shows some of the important parts of the tube of a cathode-ray

oscilloscope.

Which change in voltage results in the position of the spot on the screen movingtowards the top?! decreasing )

$ decreasing 0% increasing 2' increasing 0

May/June-2004

2 3n a stormy day+ a large+ positively-charged cloud is above a tree.!n electrical charge is induced on the tree as charged particles 4ow through it.

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What is the charge induced on the tree and how do the charged particles move?

2( The diagram shows two resistors connected in series with a cell.

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Which statement denes the potential di#erence across XY?! the power needed to drive a unit charge through the cell

$ the power needed to drive a unit charge between X and Y% the wor& done in driving a unit charge through the cell' the wor& done in driving a unit charge between X and Y

2, Which two resistor combinations have the same resistance between X and Y?

! 5 and $ 5 and 7% and R' R and 7

01 *n order to turn o# both lamps+ which is the safest switch position?

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06 ! variable potential divider has a sliding contact 7 that can be moved betweenend 5 and end .*t is connected to a constant 6 power supply+ as shown below.

What happens to the p.d. between X and Y as 7 moves down from 5 to ?! *t decreases gradually from 6 to 1 .$ *t rises gradually from 1 to 6 .% *t stays constant at 1 .' *t stays constant at 6 .

0 ! capacitor % charges when it is connected to a d.c. power supply.

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Which arrows show the direction of the conventional current when the capacitor ischarging?! ) and 0 $ ) and 8 % 2 and 0 ' 2 and 8

May/June-2003

24 Which diagram correctly shows the electric field between two charged spheres?

25 An electrical quantity is defined as ‘the energy converted by a source in driving a unit chargeround a complete circuit.’What is this quantity called?A current

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B electromotive forceC potential differenceD power 

26 The diagram shows an electric circuit.

Which pair of readings is obtained when a suitable power supply is connected between X and

 Y?

27 The diagram shows part of an electric circuit.

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What is the current in the 2∧ resistor?

A .! A B ".2 A C #. A D !. A

28 An electric heater consists of a heating element mounted on a metal reflector. The reflector isconnected to earth.Where should the switch for the heating element be connected?

A between the earth wire and the reflector B between the live wire and the heating elementC between the live wire and the neutral wireD between the neutral wire and the heating element

29 $ach of the diagrams below is a cross%section through two parallel current%carryingconductors.Which diagram correctly shows the magnetic field pattern formed by the currents in the twoconductors?

36 The electric circuit shown is used to study the charging of capacitor &.

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The neon lamp lights when the p.d. across the capacitor & reaches "" '. The capacitor & then

discharges( the lamp goes out and the p.d. across & slowly increases once more.What is the effect of increasing the resistance of )?A The lamp lights up and goes out at the same rate.B The lamp lights up and goes out less frequently.C The lamp lights up and goes out more frequently.D The lamp will not go out at all.

May/June-11

2 To charge an isolated metal sphere by induction+ the following four processes arere"uired.5 The sphere is earthed by touching it.

The earth connection is removed from the sphere.R ! charged rod is brought close to the sphere.7 The charged rod is removed.*n which order can these stages be carried out to charge the isolated metal sphere?! 5 9 9 R 9 7$ 5 9 R 9 7 9 % R 9 5 9 9 7' R 9 5 9 7 9 2( The potential di#erence :p.d.; across a )1 < resistor is = .

>ow much charge passes through the )1 < resistor in 01 seconds?! 2 % $ )= % % 61 % ' )=11 %

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2, Which changes both cause a decrease in the resistance of a copper wire?

01 The diagram shows a circuit.

What is the reading on the ammeter when the switch is open+ and the reading when

it is closed?

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0) The diagram shows a circuit.

 The lamp is a )2 W lamp and is wor&ing at normal brightness.What are the readings on the meters?

02 ! lamp rated 6 + 2 ! is switched on for 61 s.

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>ow much energy is used?! 1.2 $ 21 % )(1 ' 21

Structured Question

 June-2005

7 Fig. 7.1 shows an electrical circuit.

Fig. 7.1

(a) On Fig. 7.1, draw an arrow at A to show the direction of flow of the electrons in the wire.[1]

(b) What is the name of component X?

.................................................................................................................................... [1]

(c) State and explain how the potential difference across X varies as the light shining on it

becomes brighter.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

.................................................................................................................................... [2]

Three cells are connected in series making a battery, as shown in Fig. 8.1. The e.m.f. of

each cell is 1.5 V. A resistance of 15@ is connected to the battery.

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Fig. .1

(a) What is the total e.m.f. of the battery?

.................................................................................................................................... [1]

(b) Calculate the current in the circuit.

State the equation that you use.

current = ............................. [3]

(c) A battery can be made from cells connected in parallel, as shown in Fig. 8.2.

Fig. .2State one advantage of connecting the cells in parallel.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

.................................................................................................................................... [1]

May/June 2011[21]

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10 (a) A "* Ω resistor is used on an electronic circuit board in a television.

+ig. "." shows the bands on a resistor.

Fi! 10!2The table of +ig. ".2 shows the colour code for the bands.

(i) ,tate the colours of the bands on a "* Ω resistor.

band " ...............................................................band 2 ...............................................................band # ...............................................................

-2

(ii) /etermine the ma0imum value of resistance that can be shown with this three%bandcolour code.resistance 1 .......................................................... -"

(") +ig. ".# shows part of a circuit that includes a variable resistor ) and a battery of e.m.f.. '.

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Fi! 10!3(i) ,tate one similarity and one difference between electromotive force 3e.m.f.4 and potentialdifference 3p.d.4.similarity5 ......................................................................................................................................................................................................................................................................difference5 .....................................................................................................................................................................................................................................................................

-#