Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 49

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IMPORTANT

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A transformer consisting of $300$ turns in the primary and $150$ turns in the secondary gives output power of $2.2 k W$ . If the current in the secondary coil is $10 A$ , then the input voltage and current in the primary coil are:

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Important Questions on Electromagnetic Induction and Alternating Currents

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IMPORTANT

Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 50

An ideal transformer converts

220 V

AC to

3.3 kV

AC. It transmits the power of

4.4 kW

. If the primary coil has

600

turns, then alternating current in the secondary coil is

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 51

An alternating current having peak value $14 A$ is used to heat a metal wire. To produce the same heating effect, a constant current $i$ can be used, where $i$ is

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 52

A transformer is used to light a

100 W,

110 V

lamp from a

220 V

supply. If the supply current is

0.6 A,

the efficiency of the transformer is

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 53

A step-down transformer has turn ratio

20 : 1

. If

8 V

is applied across

0.4 Ω

secondary then the primary current will be

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 54

A step-up transformer operates on a

230 V

line and a load current of

2 A

. The ratio of primary and secondary windings is

1 : 25

. Then the current in the primary is

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 55

A transformer has efficiency

80 %

. It works at

5 kW

and

150 V

. If the secondary voltage is

240 V

, the secondary current is

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Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 56

A primary coil is connected with an

A C

source and a bulb is connected with the secondary coil. The voltage across the bulb is

6.0 V

and the current through the bulb is

0.4 A

, The turns ratio is

5 : 1 (Np : Ns = 5 : 1)

. Calculate the current in the primary coil.

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IMPORTANT

Physics Crash Course NEET>Chapter 15 - Electromagnetic Induction and Alternating Currents>Level 1>Q 57

A transformer is used to glow a

140 W - 240 V

bulb at

240 V

AC. If current in the primary coil is

0.7 A

, then the efficiency of the transformer is