Electro Magnetic Induction And Alternating Currents Question 40
Question: When 100 volt dc is applied across a coil, a current of 1 amp flows through it. When 100 volt ac at 50 cycle $ {{s}^{-1}} $ is applied to the same coil, only 0.5 ampere current flows. The impedance of the coil is [Bihar MEE 1995]
Options:
A) $ 100,\Omega $
B) $ 200,\Omega $
C) $ 300,\Omega $
D) $ 400,\Omega $
Show Answer
Answer:
Correct Answer: B
Solution:
When dc is supplied $ R=\frac{V}{i}=\frac{100}{1}=100,\Omega , $ When ac is supplied $ Z=\frac{V}{i}=\frac{100}{0.5}=200,\Omega , $