Electro Magnetic Induction And Alternating Currents Question 80
Question: The resistance of a coil for dc is in ohms. In ac, the resistance [CPMT 1987]
Options:
A) Will remain same
B) Will increase
C) Will decrease
D) Will be zero
Show Answer
Answer:
Correct Answer: B
Solution:
The coil having inductance L besides the resistance R. Hence for ac it’s effective resistance $ \sqrt{R^{2}+X_{L}^{2}} $ will be larger than it’s resistance R for dc.