Question

A circuit consisting of a constant e.m.f. 'E', a self induction 'L' and a
resistance 'R' is closed at t = 0. The relation between the current I
in the circuit and time t is as shown by curve 'a' in the fig. When one
or more of parameters E, R & L are changed , the curve 'b' is obtained
.The steady state current is same in both the cases. Thenit is possible that :

• A. E & R are kept constant & L is increased
• B. E & R are kept constant & L is decreased
• C. E & R are both halved and L is kept constant
• D. E & L are kept constant and R is decreased

Answer 1

Answer: (A), (C)

The correct options are
A E & R are kept constant & L is increased
C E & R are both halved and L is kept constant

The slope of graph in both cases can be written as,

${\left(\frac{di}{dt}\right)}_2<{\left(\frac{di}{dt}\right)}_1$

$\left(L_2\right)>\left(L_1\right)$

Thus, $E$ and $R$ are kept constant, $L$ is increased and $E$ and $R$ are both halved, $L$ is kept constant for steady state current is same in both the cases.