Electro Magnetic Induction And Alternating Currents Question 608
Question: A coil of inductance 300 mH and resistance $ 2\Omega $ is connected to a source of voltage $ 2V $ . The current reaches half of its steady state value in [AIEEE 2005]
Options:
A) 0.15 s
B) 0.3 s
C) 0.05 s
D) 0.1 s
Show Answer
Answer:
Correct Answer: D
Solution:
$ i=i_{0}( 1-{{e}^{\frac{-Rt}{L}}} ) $
Þ For $ i=\frac{i_{0}}{2} $ , $ t=0.693\frac{L}{R} $
Þ $ t=0.693\times \frac{300\times {{10}^{-3}}}{2}=0.1,sec $
