......

L in putting out an electrical fire the BESTagent to use is

2,

watercarbon dioxidesanda We! blanket

The formula for quantity of electricity in anelectrical circuit lS Q = it, The correctexpression for 't' is

~(B)ee)(D)

J.

QfiQ+QIOi

-2

External cnerg ...r such ~$ hf.::a.t~light or elcc-, .iricity can cause electrGn~~in the valence::;~"\C!i te become .

' ..(.!\.) c.ha-rge;~lt";:eC!{(:i1S(8) stationary el r.{l'ons(C') tr~pp:.:j electrons(!~b free e!ectf~-'r~~..

:.~. I~h~~.neat prod uceo t}Y~1.cur, enr inan electn ...:;aIcirc: ..tll is calcl:.lait?:t~. by h!\~ngthe forrnulll

(./".J.J.'""Zq(DJ

m:\l2Rl1Rti.f1"I-t)2;

. .

3.6J.)

L-3c6.=,Q~-~1

Il-..-- __ ~(B)(C)(D)

0.5 ASA

5.5 A15 A

Rr---------{::~~-,

~L I,~y I'! .z,~.-": -- .._;.,....-.--,l ....__ .r----.J

in the ;~b,ovecircall, the tWI) resistors (Ire ofequal value. if {,ne IS short-circuitc j thecurrent will be

(bJ---' halved{D) unchanged(C) doubled(0) quadrupled

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!for(B)(C)(0)

cross-sectional area of the cablevoltage applied to the cablelength of the cablecurrent through the cable

- 3 -

7. In which of tile following graphs is Ohm'sLaw veritied?

10. The resistance of a conductor is directlyproportional to the

1il.

(B)

VII r-~-.~

1Which switch in the circuit diagram aboveshould be closed to give a resistance of 50ohms between P and Q?

(C)(A)(B) 2(t~ '2-'(n} 4

'.1

VI

! )1/~----

1

12. In order to calcutate the r.m.s. v.,lue ct alla.c. quantity one should

(1-\) multiply the avez uge value byO.:C36(B) subtract 0:/07 from the peak value(C) add 0.636 to the peak valueQ:;?J' multiply the pc.'ik value hy {1-707

\",h~\.h('[the foi-o' .tl1.:.>rnili\~rif .~ c~~:"!('?

(A)(B)(C)CD}/\..,....

instantaneous v(:;0 ON TO THE NEXT PAGE

16. Which of the following heanng-elediagrams would produce maximum heat?

(A)

11--- +-----r--\( N \_'-/--_-/--

\-

s

0--'The a.c. wave form devetoped across the coilshown above can be converted to d.c, byusing

(B)

(A) rectifiers(5) inverterst,py" slip rings.r reactors

(C)

I~ J;hich of the following circuit diagrams arethe THREE resistors connected in parallel?

(0)

(A)

. '.)

p_.--fi.

In the pli:raHel circuit' ",h",Jvm above, tht'power developed in th.eresi stances R: and R~are P: and P2 respectively.

(C)

The toi.~l power, P, will be given by theformula(D)

(A) p:: {II + 41~)I(B) ->P= (V/R.! + V/P--:::)i[;v P=f\+Pz(0) 'UP .",:1/1\ + liP:z

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1~'o. The B.S. graphical symbol for an electricbell is

(A) (0~

(B) \:;J--(C) (0(D) Q~,

i9. 1\ "Voltmeter which has an f.s.d, of 120 isreading centre scale when the functionswitcn is se.tat lhe 1.2 V range. The actualmeter reading, in volts. is

fA)' '" 0.06(B.i 0.6(C) 6.0(,r.;;: 60.0

20. ~;'Ybichof the following (p.m1.hies is a!(H;~i!ig-cnil. instrument designed iom;:aSUfi:"?

l. Ahc:mating currentH. Direct currentm. Electrical energy

:.'.:"i"; J only).~.\ H only(C) II and IiI only(D'i L It and HI

- 5 -

2l.

The milliammeter, in the diagram above,reads

/

i.!>'J/'(B)(C)tTI)

0.04 A0.4 A4.0A40A

22. Which of the following diagrams indicatesthe connections to give the HIGHEST volt-meter reading?

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0.15 s1.5 s15 s150 s

r -7 -30, How much time does it take for 6 kilojoules

of energy to beexpen

!38. Buildings are protected from lightning byusing lightning arrestors which consist of a

. ,

(A) long, slender. plastic rod below thebuilding roof and connected toearth by a light metal cable

short. round. metal rod below thebuilding roof and connected toearth by a light metal cable

long, slender, metal rod above thebuilding roof and connected toeann by a heavy metal cable

short, round, plastic rod above thebuilding roof and connected toearth by a heavy cable

(B)

(D)

39. If a glass rod is rubbed with silk. the natureoJ'the charge will be .

(A) induced(8) neutral(C) positive91) .~ negative

40 Electricalinstallations are tested so as to

(A) check frequency s!?:sbmty(B) ensure that they are completedfC) determine how much to pay (he

electrician....,Q>Y" detect possible faults

41. A 'lightning arrestor' is used for

(A) IocaringIightning during ~;stormiB) increasing the frequency range of

an antenna(C&/" discharging static electricity from~~~

the atmosphe .e(D) increasing the selecnviiy of an an-

trona

- 8 -

45.

42 . A relay is a device with an armature whichis operated by

(A) manual force(B) /' mechanical pressure~J magnetic force(D) electrical force

43. The part of the telephone into which onespeaks is called the

~(B)(C)(D)

microphonereceiverdiaphragmdisc

44.

Whici'} type of electric belt i.ShO\Jl31 in thediagram above'?

(1}}/(8)(C)(0)

Trembler bellSingle-stroke b-~:UContinuous ringing bellPolarised bell

In d.c. power supplies, the zener diode isresponsible for

(A) mutual induction(B) energy storage . I(C) voltage regulation(p.)" filtering..;-

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46.

Push

Fuse

Battery .:::=...

I

In the diagram above, an earth fault occursat point X. This will result in

(A) any bell ringing whichever push ispressed

the fuse blowing befnre any l}1.lSh ispressed ,

all three bells nnging before anypush is pressed

bells 2 and 3 beccming short-circuited together

(B.) .

V1hal effect does an ambient temperaturegreererthan 30C have on the current ratingof a. COndlJCCOc?

~) The current rating is decreased,~) The current rating is increased.(C) The current ratlng reraains un-

changed,(D) The current rating is.muitiplip;! by

the voltage drop.

Vi&v..\l {niipt',ction of an electrical installa-,jon is to contirm the condition of

~A)W)fC)(D)/';0"

. polarityCI);;l!:iuCtorcontinuityinsulation resisrancecablesnd terminations

-9 -

normally closed switchesnormally open switchestoggle switchespush switches

49. Switches which open when they are actu-ated are

eM/'(B)(C)(0)

50. When a current flows through a mercuryvapour. it produces

,(A)

~(D)

ultraviolet lightinfrared lightyellow lightinfrared waves

51. Which of tile following features of an elec-trolytic capacitor must be strictly observed?

ie.~) Polarity(8) Temperaturerating(C) Size(D)' Current rating

52. Incandescent lamps produce light as a resultof current passing through a

(AtJrD(C)(D)

ballastfilamentstartergas

53.: Which of the following is true of a stepdowntransformer?

!)

- 10 -

A.C. voltage may be increased by means ofalan

(A)(B)JKJ(D)

generatorrectifiertransformeralternator

58. Which device in a d.c. generator convertsthe generated a.c. voltage to a d.c. voltage?

(A)(B)(C)(D) _V"'"

ArmatureField coilStatorCommutator

59. Which of the following is the correct sym-bol for a switched socket outlet?

(~

(13)

(C)

(D)

ifJf'

I

XAX

The resistor which is placed in parallel withrhe meter movement of an ammeterisknownasa

60

(AY shunt(B) multiplier(C) multirange resistor(D) calibrating resistor

tFYOF FP~ISH "BEFORE THvlE IS CALLED, CHECK YOUR WORK ON THIS TEST.

55. Which of the following synchronous speedscan be identified as that of a 60 Hz 4-poleinduction type motor?

(A) 1400rpm(B) 1600 rpm~ 1800rpm(0) 2000 rpm

::G. A.C. is preferred to d,c, for transmission ofetectrtcal energy because it is

,.(A) easier to ilandle(Ht cheaperto maintain_(ej easily transformed to required

values(D) easier 10 generate

:';..;-, \Vhich of the following symbols representsa main control'!

Vi) c=t-'(11,}'" t:;8j~"

(C) k2J(D) E3