Question

-7-
6031A - PGET-PHY - 2020
42. A current of 1.1 A flows through a coil, when connected to a 110V DC
When 110V AC of 50 Hz is applied to the same coil, only 0.5 A current
filows. Calculate the impedance of the coil.
(A) 302.52 (B) 2202
(C) 55002 (D) 100
Low many times
will reverse its​

Answer 1

Answer:

42 = ANSWER

For dc,

I=1.1A

V=110V

V=IR

therefore, R=1.1110=100Ω

For ac,

V=110V

R=100Ω

I=0.5A

Z=IV=0.5110=220Ω

Frequency ν=50Hz

wkt

Z=R2+ωL2=R2+4π2ν2L2220=1002+4π2(50)2L2L=0.389H