Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 14

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An arc lamp requires a direct current of $10 A$ at $80 V$ to function. If it is connected to a $220 V (rms), 50 Hz AC$ supply, the series inductor needed for it to work is close to

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Important Questions on Alternating Current

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Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 15

For an RLC circuit driven with voltage of amplitude

v_{m}

and frequency

ω_{0} = \frac{1}{\sqrt{L C}}

the current exhibits resonance. The quality factor,

Q

is given by

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Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 16

In an A.C. circuit, the instantaneous

e . m . f .

and current are given by

e = 100 \sin (30 t) V

,

I = 20 \sin (30 t - \frac{π}{4}) A

. In one cycle of A.C., the average power

(in watt)

consumed by the circuit and the wattless current

(in ampere)

are, respectively:

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Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 17

A power transmission line feeds input power at

2300 V

to a step down transformer with its primary windings having

4000

turns. The output power is delivered at

230 V

by the transformer. If the current in the primary of the transformer is

5 A

and its efficiency is

90 %,

the output current would be

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Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 18

A series

A C

circuit containing an inductor

(20 mH),

a capacitor

(120 μ F)

and a resistor

(60 Ω)

is driven by an

A C

source of

24 V / 50 Hz .

The energy dissipated in the circuit in

60 s

is:

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Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-3>Q 19

In the above circuit $C = \frac{\sqrt{3}}{2} mF, R_{2} = 20 Ω L = \frac{\sqrt{3}}{10} H$ and $R_{1} = 10 Ω$ Current in $L - R_{1}$ path is $I_{1}$ and in $C - R_{2}$ path it is $I_{2}$ . The voltage of A.C. source is given by $V = 200 \sqrt{2} \sin (100 t) Volts$ , the phase difference between $I_{1}$ and $I_{2}$ is :