Home
Class 12
PHYSICS
When a DC voltage of 200 V is applied to...

When a DC voltage of 200 V is applied to a coil of self inductance (2/`sqrt 3`/`pi`)H a current of 1A flows through it . But by replacing DC source with AC source of 200 V , the current in the coil is reduced to 0.5A . Then the frequency of AC supply is

A

30 Hz

B

60 Hz

C

75 Hz

D

50 Hz

Text Solution

Verified by Experts

The correct Answer is:
D
Resistance of coil(R ) = `200V/1A = 200Omega`
With AC source , `I = 200/sqrt R^(2)` or `0.5 = 200/sqrt(R^(2)+X_(L)^(2))
`implies` R^(2) + (2pifL)^(2) = (400)^(2)`
`implies(2pif xx 2sqrt 3/pi )^(2)` = `(400)^(2)- (200)^(2)= 200 xx 600`
`impliessqrt 3 = 2sqrt 3 xx 100 implies f = 50 Hz`
Promotional Banner

Similar Questions

Explore conceptually related problems

Magnetic flux of 5 microweber is linked with a coil, when a current of 1mA flows through it. What is the self-inductance of the coil?

If a current of 10 A changes in one second through a coil, and the induced emf is 20 V, then the self-inductance of the coil is

A 100W bulb is connected to an AC source of 220V , 50Hz . Then the current flowing through the bulb is

When 100 V dc is applied across a coil, a current of 1A flows through it and when 100 V ac of 50 Hz is applied to the same coil, only 0.5 flows The inductance of coil is

Self-inductance of a coil is 50mH. A current of 1 A passing through the coil reduces to zero at steady rate in 0.1 s, the self-induced emf is

When 100 V DC is applied across a solenoid, a steady current of 1 A flows in it. when 100V AC is applied across the same solenoid, the current drops to 0.5 A. If the frequency of the Ad source is 150// sqrt3pi Hz , the impedance and inductance of the solenoid are

When 100 volt d.c. is applied across a solenoid, a current of 1.0 A flows in it. When 100 volt a.c. is applied across the same coil, the current drops to 0.5 A. If the frequency of a.c. source is 50 Hz the impedance and inductance of the solenoid is

When 100" volt" dc is applied across a coil, a current of 1 amp flows through it, when 100 V ac of 50 Hz is applied to the same coil, only 0.5 amp flows. Calculate the resistance and inductance of the coil.

When an inductor coil is connected to an ideal battery of emf 10V, a constant current 2.5 A flows. When the same inductor coil is connected to an ac source of 10V and 50 HZ then the current is 2A. Find out the inductance of the coil.

A coil of inductance 0.2 H and 1.0 ohm resistance is connected to a 90 V source. At what rate will the current in the coil grow at the instant the coil is connected to the source?