Electro Magnetic Induction And Alternating Currents Question 327
Question: A coil of inductance 8.4 mH and resistance 6 W is connected to a 12 V battery. The current in the coil is 1.0 A at approximately the time [IIT-JEE (Screening) 1999; UPSEAT 2003]
Options:
A) 500 sec
B) 20 sec
C) 35 milli sec
D) 1 milli sec
Show Answer
Answer:
Correct Answer: D
Solution:
Peak current in the circuits $ i_{0}=\frac{12}{6}=2A $
Current decreases from 2A to 1A i.e., becomes half in time
$ t=0.693\frac{L}{R}=0.693\times \frac{8.4\times {{10}^{-3}}}{6}=1milli,sec. $
