Question

A resistor, an inductor, and ideal battery, and a switch are connected in series. Just after the switch is closed, which of the following are zero?
a) the current and the voltage across the inductor
b) the current and the voltage across the resistor
c) the voltage across the inductor and the voltage across the resistor
d) all of the above.
Explain your reasoning.

Answer 1

Answer:

b) the current and the voltage across the resistor

Explanation:

As soon as we close the switch then the current in the circuit will be zero because the inductor connected in series will not allow to change the current through it due to its inertial property

Since initial current through the inductor is zero so after connecting the key the current will still remains zero and then it will start increasing

The equation for current is given as

$i = i_o(1 - e^{-Rt/L})$

so as soon as the key is closed the current in the circuit is zero and hence the voltage across the resistor is also zero as we know

$V_r = i R = 0$

so correct answer will be

b) the current and the voltage across the resistor