Electricity

1

Which one of the following devices is non-ohmic?

  1. Conducting copper coil
  2. Electric heating coil
  3. Semi conductor diode
  4. Rheostat
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2

During Short circuiting, the current flowing in the electrical circuit

  1. increases instantaneously
  2. reduces substantially
  3. varies continuously
  4. does not change
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3

The electric field inside a perfectly conducting hollow object is

  1. infinite
  2. dependent upon the shape of the object
  3. zero
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4

Van de graaff generator is used for

  1. generating large currents
  2. accelerating charged particles
  3. generating electric field
  4. generating high-frequency voltage
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5

Two conducting wires A and B are made of same material. If the length of B is twice that of A and the radius of circular cross-section of A is twice that of B, then their resistances RA and RB are in the ratio

  1. 1 : 2
  2. 2 : 1
  3. 1 : 4
  4. 1 : 8
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6

Which one of the following circuit elements is an active component?

  1. Transistor
  2. Capacitor
  3. Resistor
  4. Inductor
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7

A fuse is used in the electric circuit to

  1. break the circuit when power gets off
  2. complete the circuit for flow of current
  3. break the circuit when excessive current flows through the circuit
  4. indicate if the current is flowing uninterrupted
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8

If two conducting spheres are separately charged and then brought in contact

  1. the total charge of the two spheres is conserved
  2. both the total energy and the total charge are conserved
  3. the final potential is always the mean of the original potential of the two spheres
  4. the total energy of the two spheres is conserved
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9

When you pull out the plug connected to an electrical appliance, you often observe a spark. To which property of the appliance is this related?

  1. Resistance
  2. Wattage
  3. Capacitance
  4. Inductance
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10

Electricity is produced through dry cell from

  1. Nuclear Energy
  2. Mechanical Energy
  3. Chemical Energy
  4. Thermal Energy
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11

Two resistors of resistance 2 Ω and 4 Ω when connected to a battery will have

  1. same current flowing through them when connected in parallel
  2. same current flowing through them when connected in series
  3. same potential difference across them when connected in series
  4. different potential difference across them when connected in parallel
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12

An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?

  1. 1 A
  2. 2 A
  3. 4 A
  4. 5 A
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13

In an electrical circuit two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be

  1. 5 J
  2. 10 J
  3. 20 J
  4. 30 J
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14

In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?

  1. Brightness of all the bulbs will be the same
  2. Brightness of bulb A will be the maximum
  3. Brightness of bulb B will be more than that of A
  4. Brightness of bulb C will be less than that of B
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15

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be

  1. 100%
  2. 200%
  3. 300%
  4. 400%
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16

A cylindrical conductor of length l and uniform area of cross-section A has resistance R. Another conductor of length 2l and resistance R of the same material has area of cross section

  1. A/2
  2. 3A/2
  3. 2A
  4. 3A
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17

What is the maximum resistance which can be made using five resistors each of 1/5 Ω?

  1. 1/5 Ω
  2. 10 Ω
  3. 5 Ω
  4. 1 Ω
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18

A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly

  1. 1020
  2. 1016
  3. 1018
  4. 1023
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19

Electrical resistivity of a given metallic wire depends upon

  1. its length
  2. its thickness
  3. its shape
  4. nature of the material
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20

In the following circuits, heat produced in the resistor or combination of resistors connected to a 12 V battery will be

  1. same in all the cases
  2. minimum in case (i)
  3. maximum in case (ii)
  4. maximum in case (iii)
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21

In an electric bulb, light is produced due to the glowing of

  1. the glass case of the bulb.
  2. the thin filament.
  3. the thick wires supporting the filament.
  4. gases inside glass case of the bulb.
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