1. Electric current originates from which part of an atom?
A. nucleus
B. entire atom acting as a unit
C. positively charged protons
D. negatively charged electrons
Ans. D
2. The resistance of the wire varies inversely as:
A. Area of cross section
B. Resistivity
C. Length
D. Temperature
Ans. A
3. Voltage is a form of:
A. Kinetic energy
B. Potential energy
C. both Potential and Kinetic energy
D. None of the above
Ans B
4. Electric pressure is also called
(a) resistance
(b) power
(c) voltage
(d) energy
Ans: c
5.The substances which have a large number of free electrons and offer a low resistance are called
(a) insulators
(b) inductors
(c) semi-conductors
(d) conductors
Ans: d
6. Ohm’s law is not applicable to
(a) vacuum tubes
(b) carbon resistors
(c) high voltage circuits
(d) circuits with low current densities
Ans: a
7. Which is the best conductor of electricity ?
(a) Iron
(b) Silver
(c) Copper
(d) Carbon
Ans: b
8. All of the following are equivalent to watt except
(a) (amperes) ohm
(b) joules/sec.
(c) amperes x volts
(d) amperes/volt
Ans: d
9. The rating of a fuse wire is always expressed in
(a) ampere-hours
(b) ampere-volts
(c) kWh
(d) amperes
Ans: d
10. A closed switch has a resistance of
(a) zero
(b) about 50 ohms
(c) about 500 ohms
(d) infinity
Ans: a
11.Which of the following quantities remain the same in all parts of a series circuit ?
(a) Voltage
(b) Current
(c) Power
(d) Resistance
Ans: b
12.Resistance of a tungsten lamp as applied voltage increases
(a) decreases
(b) increases
(c) remains same
(d) none of the above
Ans: b
13. If the efficiency of a machine is to be high, what should be low ?
(a) Input power
(b) Losses
(c) True component of power
(d) kWh consumed
(e) Ratio of output to input
Ans: b
14.A glass rod when rubbed with silk cloth is charged because
(a) it takes in proton
(b) its atoms are removed
(c) it gives away electrons
(d) it gives away positive charge
Ans: c
15 Bulbs in street lighting are all connected in
(a) parallel
(b) series
(c) series-parallel
(d) end-to-end
Ans: a
16. The resistance of a conductor is directly proportional to :
(a) its area of cross-section
(b) density
(c) melting point
(d) length
Ans D
17 Formula for electric power is
(a)P= V2 I
(b)P=V I
(c) P=I/V
(d)P=V/I
Ans B
18. In electric heating appliances, the material of heating element is
(a)Brass
(b) Nichrome
(c) Silver
(d) Copper.
Ans B
19.The relation between H ;I is called
(a)Newton’ s law
(b)Faraday’ s law
(c)Joule’s law
(d) Ohm’ s law
Ans C
20. Heating of a current carrying conductor is due to
(a) Loss of kinetic energy by atoms
(b) Loss of kinetic energy by electrons
(c)Attraction between electrons
(d)Repulsion between electrons & protons
Ans. B
21. The total work done by an electrical appliance during its operation, is called electrical
(a) Current
(b) Power
(c) Energy
(d) potential difference
Ans. C
22.In parallel combination of n cells, we obtain
(a) more voltage
(b) more current
(c) less voltage
(d) less current
Ans B
23 Consider the following statements.
An ordinary light bulb has a rather short life because the
1. Filament wire is not uniform.
2. Bulb cannot be evacuated completely.
3. Wires supporting the filament melt at high temperatures.
Which of the above statements are correct?
(A) 1 and 3
(B) 2 and 3
(C) 1 and 3
(D) 1, 2 and 3
Ans D
24. Electricity consumption bill is based on the measurement of
1. Watt
2. Voltage
3. Ohm
4. Ampere
Select your answer of the following codes. [40th BPSC (Pre) 1995]
(A) Only 1
(B) 1 and 2
(C) 2 and 3
(D) 1 and 4
Ans A
25. The device used for converting alternating current to direct current is called
(A) Inverter
(B) Rectifier
(C) Transformer
(D) Transmitter
Ans B
26.A mobile phone charger is
(A) An inverter
(B) A UPS
(C) A step up transformer
(D) A step down transformer
Ans D
27. Domestic electrical wiring is basically a
(A) Series connection
(B) Parallel connection
(C) Combination of series and parallel connections
(D) Series connection within each room and parallel connective elsewhere
Ans B
28.Which element is the best conductor of electricity?
(A) Silver
(B) Copper
(C) Aluminium
(D) Iron
Ans A
29. In a three-pin electrical plug longest pin should be connected to
(A) Ground terminal
(B) Live terminal
(C) Neutral terminal
(D) Any terminal
Ans A
30. Turbines and Dyanamos are used to convert which energy to electrical energy?
(A) Chemical energy
(B) Solar energy
(C) Mechanical energy
(D) Magnetic energy
Ans C
31 What does the internal resistance of a cell mean?
(a) The resistance of the material used in the cell
(b) The vessel of the cell
(c) The electrodes of the cell
(d) The electrolyte used in the cell
Answer: (d)
32 What is the principle behind thermocouple
(a) Joule effect
(b) Thomson effect
(c) Seebeck effect
(d) Peltier effect
Answer: (c)
33 On which of the given resistance does not depend :
A. Length of conductor
B. Area of cross-section
C. Temperature
D. Density
Ans D
34 An electric fuse works on the:
A. Chemical effect of current
B. Magnetic effect of current
C. Lighting effect of current
D. Heating effect of current
Ans D
35. Ampere second could be the unit of
(A) power
(B) conductance
(C) energy
(D) charge.
Ans D
36 Which of the following is not the same as watt?
(A) joule/sec
(B) amperes/volt
(C) amperes x volts
(D) ( amperes )2 x ohm.
Ans B
37. Kilowatt-hour(kWh) is a unit of?
a) Current
b) Power
c) Energy
d) Resistance
Ans C
38 The SI unit of power is?
a) kW(kilo-watt)
b) J/s(joules per second)
c) Ws(watt-second)
d) J/h(joules per hour
Ans B
39.The unit of work is joule. The other physical quantity that has same unit is
(a) power
(b) velocity
(c) energy
(d) force
Ans C
40 When a coolie walks on a horizontal platform with a load on his head, the work done by the coolie on the load is zero.
a) True
b) False
Ans A
41 A moving hammer drives a nail into the wood. It has kinetic energy.
a) True
b) False
Ans A
42 Electric motors operating at low
voltages tend to burn out because
(A) They draw more current which is inversely proportional to the voltage
(B) They draw more current which is inversely proportional to the square root of the voltage
(C) They draw heat proportional to v 2
(D) Low voltage sets in electrical discharge
Ans A
43 If potential difference and current flowing through a wire is increased twice each, then electric power
(A) Will remain unaffected
(B) Will increase four times
(C) Will increase two times
(D) Will decrease half
Ans B
44 Alternate current is not preferable
(A) To charge storage battery
(B) To run/start an electric motor
(C) To transmit electric power
(D) To heat up electric toaster
Ans A
45 Electric current passing through the circuit produces
(a) magnetic effect
(b) luminous effect
(c) thermal effect
(d) chemical effect
Ans: c
46. Which of the following quantities remain the same in all parts of a series circuit ?
(a) Voltage
(b) Current
(c) Power
(d) Resistance
Ans: b
47.The filament of an electric bulb is made of
(a) carbon
(b) aluminium
(c) tungsten
(d) nickel
Ans: c
48 Which one of the following does not have negative temperature co-efficient ?
(a) Aluminium
(b) Paper
(c) Rubber
(d) Mica
Ans: a
49 With rise in temperature the resistance of semi-conductors
(a) decreases
(b) increases
(c) first increases and then decreases
(d) remains constant
Ans: a
50 With rise in temperature the resistance of pure metals
(a) increases
(b) decreases
(c) first increases and then decreases
(d) remains constant
Ans: a
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