In the circuit shown in the figure, the switch was kept in $position - 1$ for a very long time and then at $t = 0$ it is shifted to $position - 2$ . The current in the circuit immediately after that is $i = \dfrac{a}{b}A$ , then the value of $a + b$ is

Question

In the circuit shown in the figure, the switch was kept in

position - 1

for a very long time and then at

t = 0

it is shifted to

position - 2

. The current in the circuit immediately after that is

i = \dfrac{a}{b}A

, then the value of

a + b

is

Quantrex Academy · Accepted Answer

Correct answer: 7

The total flux, before and after the position change of the switch, remains the same

${L}_{1}{i}_{1} = {L}_{2}{i}_{2}$

${L}_{1} = 5H$ , ${i}_{1} = 4A$ and ${L}_{2} = 15H$

$5 \times 4 = 15 \times i$

$⇒ i = \dfrac{4}{3} = \dfrac{a}{b}$

$⇒ a + b = 7$

In the circuit shown in the figure, the switch was kept in position...