# NCERT Class 12/Current Electricity Class 12 MCQs Questions Sample Test,Sample questions

## Question: `1 kilowatt hour is commonly known as :`

1.unit

3.1 curie

4.None of the above

Posted Date:-2021-12-16 10:27:18

## Question: `A 5 A fuse wire can with stand a maximum power of 1 W in circuit. The resistance of the fuse wire is:`

1.0.2 â„¦

2.5 â„¦

3.0.4 â„¦

4.0.04 â„¦

Posted Date:-2021-12-16 08:33:14

## Question: `A galvanometer acting as a volt meter will have with its coil.`

1.a high resistance in parallel

2.a high resistance in series

3.a low resistance in parallel

4.a low resistance in series

Posted Date:-2021-12-16 08:45:40

## Question: `A potential difference of 10 V is applied across a conductance of 2 S. The current in the conductor will be :`

1.20 A

2.5 A

3.0.2 A

4.None of the above

Posted Date:-2021-12-16 10:23:06

## Question: `A potential difference of 10 V is applied across a conductance of 2 S. The current in the conductor will be :`

1.20 A

2.5 A

3.0.2 A

4.None of the above

Posted Date:-2021-12-16 10:23:15

## Question: `A potential difference of 10 V is applied across a conductance of 2 S. The current in the conductor will be :`

1.20 A

2.5 A

3.0.2 A

4.None of the above

Posted Date:-2021-12-16 10:23:18

## Question: `A uniform w ire connected across a supply produces heat H per second. If wire is cut into three equal parts and all the parts are connected in parallel across the same supply, the heat produced per second will`

1.H/9

2.9 H

3.3 H

4.H/3

Posted Date:-2021-12-16 10:46:07

## Question: `A wire of resistance 3 â„¦ is cut into three pieces, which are then joined to form a triangle. The equivalent resistance between any corners of the triangle is :`

1.2/3 â„¦

2.3/2 â„¦

3.1/2 â„¦

4.1/3 â„¦

Posted Date:-2021-12-16 08:13:23

## Question: `A wire P is half the diameter and half the length of a wire Q of similar material. The ratio of resistances of P to that 0 is:`

1.4 : 1

2.8 : 1

3.2 : 1

4.1 : 2

Posted Date:-2021-12-16 10:57:44

## Question: `An electric heating element consumes 500 W, when connected to a 100 V line. If the line voltage becomes 150 V, the power consumed Will be:`

1.500 W

2.730 W

3.1000 W

4.1125 W

Posted Date:-2021-12-16 10:44:06

## Question: `Copper wire is used as connecting wire because :`

1.copper has high electrical resistivity

2.copper has low electrical resistivity

3.copper has low electrical conductivity

4.copper has high value of elasticity

Posted Date:-2021-12-16 10:30:01

## Question: `Emf is measured in :`

1.joule

2.joule/coulomb

3.joule-coulombs

4.joule/coulomb/metre

Posted Date:-2021-12-16 10:26:45

## Question: `Given three equal resistors, how many different combinations (taken all of them together) can be made?`

1.3

2.4

3.5

4.6

Posted Date:-2021-12-16 08:08:25

## Question: `How many different resistances are possible with two equal resistors?`

1.2

2.3

3.4

4.5

Posted Date:-2021-12-16 08:07:56

## Question: `How many joules are equal to I kWh ?`

1.3.6 Ã— 104

2.3.6 Ã— 105

3.3.6 Ã— 106

4.None of the above

Posted Date:-2021-12-16 10:27:54

## Question: `How much electric energy is consumed by a 100 W lamp used for 6 hours everyday for 30 days?`

1.18 kJ

2.18 kWh

3.1.8 J

4.None of the above

Posted Date:-2021-12-16 08:26:14

## Question: `If a certain piece of copper is to be shaped into a conductor of minimum resistance, its length (L) and cross-sectional area (a) shall respectively be :`

1. L, 2A

2.L/2, 2A

3.2L, 2A

4.2l, A/2

Posted Date:-2021-12-16 08:11:02

## Question: `In a Wheatstone bridge, the resistance each arm is 10 â„¦. If the resistance galvanometers is also 10 â„¦, then effective resistance of the bridge will be :`

1.40 â„¦

2.20 â„¦

3.10 â„¦

4.5 â„¦

Posted Date:-2021-12-16 10:51:52

## Question: `In questions 135, w hen the wires are connected in series, the heat produced in the thinner wire is H1 and that in the thicker wire is H2. Then :`

1.H1 = H2

2.H1 < H2

3.H1 > H2

4.H1 > H2

Posted Date:-2021-12-16 08:31:12

## Question: `In the above question, the conductance:`

1.(a) halved

2.doubled

3.unchanged

Posted Date:-2021-12-16 08:15:45

## Question: `Kirchhoffs first and second laws for electrical circuits are consequences of:`

1.conservation of energy

2.conservation of electrical charge and energy respectively

3.conservation of electric charge

4.neither conservation of energy nor electric charge

Posted Date:-2021-12-16 08:32:17

## Question: `n an experiment with potentiometer, null point with a cell is found at 240 cm. When the cell is shunted with a resistance 2 â„¦, the null point becomes 120 cm internal resistance of cell is :`

1.4 â„¦

2.2 â„¦

3.1â„¦

4.1/2 â„¦

Posted Date:-2021-12-16 10:34:00

## Question: `n India electricity is supplied fordomestic use at 220 V. It is supplied at 110 V in U.S.A. If the resistance of a 60 W bulb use in India is R. the resistance of a 60 W bulb for use in USA will be:`

1.2 R

2.R

3. R/2

4.R/4

Posted Date:-2021-12-16 10:47:40

## Question: `n resistances, each of R â„¦, are connected in parallel gives an equivalent resistance of R â„¦. If these resistances were , connected in series, the combination would have a resistance in â„¦ is equal to`

1. nÂ²R

2.R/nÂ²

3.R/n

4. nR

Posted Date:-2021-12-16 10:18:02

## Question: `Ohmâ€™s law is valid when the temperature of conductor is :`

1.very low

2. very high

3.varying

4. constant

Posted Date:-2021-12-16 10:25:07

## Question: `Potentiometer measures the potential difference more accurately than a voltmeter because:`

1. It has a wire of high resistance

2.It has a wire of low resistance

3.It does not draw current from external circuit

4. It draws heavy current from external circuit

Posted Date:-2021-12-16 10:49:58

## Question: `Siemen is the unit of:`

1.resistance

2.conductance

3.specific conductance

4.None of the above

Posted Date:-2021-12-16 08:25:34

## Question: `Specific resistance of ali metals is mostly affected by:`

1.temperature

2.pressure

3.magnetic field

4.volume

Posted Date:-2021-12-16 08:09:01

## Question: `Suppose H1 is the heat generated per second in the filament of a 100 W, 250 V lamp and H2 is the heat generated in the filament of a 200 W, 250 V lamp. Then H1/H2 is equal to:`

1.1

2.2

3.1/2

4.1/4

Posted Date:-2021-12-16 08:26:59

## Question: `The emf of a car battery is about:`

1.2.5 V

2.4.5 V

3.8.6 V

4.12 V

Posted Date:-2021-12-16 10:25:46

## Question: `The example of a non-ohmic resistance is:`

1.copper wire

2.fi lament lamp

3.carbon resistor

4.diode

Posted Date:-2021-12-16 08:09:45

## Question: `The heat sensitive device whose resistivity changes very rapidly with change of temperature is called a :`

1.resistor

2.super-conductor

3.thermocouple

4.thermistor

Posted Date:-2021-12-16 10:30:48

## Question: `The length and radius of an electric resistance of a certain wire are doubled simultaneously, then the:`

1.resistance will be doubled and specific resistance will be halved

2.resistance will be halved and specific resistance will remain uncharged

3.resistance will be halved and the specific resistance will be doubled

4.resistance and specific resistance will both remain uncharged

Posted Date:-2021-12-16 08:34:09

## Question: `The length of a conductor is halved. Its resistance will be :`

1.halved (b) (c) (d)

2.doubled

3.unchanged

Posted Date:-2021-12-16 08:14:35

## Question: `The number of electrons that constitute 1 A of current is:`

1.6.25 Ã— 1016

2.6.25 Ã— 1017

3.6.25 Ã— 1018

4.6.25 Ã— 1019

Posted Date:-2021-12-16 08:07:16

## Question: `The phenomenon of super-conductivity was discovered by :`

1.Ohm

2.Onnes

3.Edison

4.None of the above

Posted Date:-2021-12-16 10:31:40

## Question: `The resistance of a human body is about:`

1.2 â„¦

2.120 â„¦

3.12 Kâ„¦

4.120 Mâ„¦

Posted Date:-2021-12-16 08:06:31

## Question: `The specific resistance of a conductor increases with :`

1.increase in temperature

2.increase in cross-sectional area

3.decrease in length

4.decrease in cross-sectional area

Posted Date:-2021-12-16 10:33:01

## Question: `The specific resistance of a rod of copper as compared to that of thin wire of copper is :`

1. less

2.more

3.same

4.depends upon the length and area of cross-section of the wire

Posted Date:-2021-12-16 08:12:07

## Question: `The speed at which tjie current travels in a conductor is nearly:`

1.3 Ã— 104 ms-1

2.3 Ã— 106 ms-1

3.3 Ã— 108 ms-1

4.3 Ã— 1010 ms-1

Posted Date:-2021-12-16 08:05:47

## Question: `The temperature coefficient of resistance is expressed in :`

1.Â°C

2.Â°C-1

3.mÂ°C-1

4.None of the above

Posted Date:-2021-12-16 10:28:46

## Question: `Thermo electricity was discovered by:`

1.Joule

2.Peitier

3.Thomson

4.Seebeck

Posted Date:-2021-12-16 11:04:23

## Question: `Thermo emf is the order of:`

1.10 V

2.10 V

3.10 V

4.10-12 V

Posted Date:-2021-12-16 11:06:57

## Question: `Two bulbs 25 W, 220 V and 100 W, 220 V are given. Which has higher resistance?`

1.25 W

2.100 W

3.both bulbs have equal resistance

4.resistance of bulbs can not be compared

Posted Date:-2021-12-16 10:49:05

## Question: `Two equal resistors are connected in series across a battery and consume a power of P. If these are connected in parallel, then theâ€™ power consumed will be:`

1.2P

2.4 P

3.p/4

4.P

Posted Date:-2021-12-16 11:00:33

## Question: `Two wires of copper are of the same length butâ€™have different diameters. When they are connected in series across a battery, the heat generated is H1 When connected in parallel across the same battery, the heat generated during the same time is H2 Then :`

1.H1 = H2

2.H1 < H2

3.H1 > H2

4.H1 > H2

Posted Date:-2021-12-16 08:27:41

## Question: `What is the resistance across A and B in the network in Fig.?`

1. R

2.2 R

3.R/2

4.6 R

Posted Date:-2021-12-16 10:58:31

## Question: `When the wires are connected in parallel, the heat produced in the thinner wire is H1 and that in the thicker wire is H2 Then:`

1. H1 = H2

2.H1 < H2

3.H1 > H2

4. H1 â‰¥ H2

Posted Date:-2021-12-16 10:59:35

## Question: `When three identical bulbs of 60 W, 200 V rating are connected in series to a 200 V supply, the power drawn by them will be:`

1.20 W

2.60 W

3.180 W

4.10 W

Posted Date:-2021-12-16 10:17:02

## Question: `Which of the following has a negative temperature coefficient of resistance ?`

1.Tungsten

2.Carbon

3.Nichrome

4.Platinum

Posted Date:-2021-12-16 10:41:56

## Question: `Why is the Wheatstone bridge more accurate than other methods of measuring resistances: â€˜`

1.It is a null method

2. It is based on Kirchhoffs laws

3.It has four resistances

4.It does not involve ohmâ€™s law

Posted Date:-2021-12-16 10:18:42

## More MCQS

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