An e.m.f. of 15 V is applied in a circuit containing a 5 H inductance and a 10 Ω resistance. The ratio of the currents at time t=∞ and, at t=1 second is
Current in the growing circuit is given by
I=I0 ⎡⎢ ⎢⎣1−e⎛⎝−RtL⎞⎠⎤⎥ ⎥⎦
When, t=∞, I=I0
At t=1 sec
It=1=I0⎡⎢ ⎢⎣1−e⎛⎝−RL⎞⎠⎤⎥ ⎥⎦
=1.5×⎡⎢ ⎢⎣1− e⎛⎝−105⎞⎠⎤⎥ ⎥⎦
Hence, (B) is the correct option.