A constant voltage of 25 V is applied to a series L-R circuit at t=0, by closing a switch. What is the potential difference across the resistor and the inductor at time t=0 ?

Question

A constant voltage of 25 V is applied to a series L-R circuit at t=0, by closing a switch. What is the potential difference across the resistor and the inductor at time t=0 ? (A) 0 V , 25 V (B) 12.5 V , 1.25 V (C) 10 V , 15 V (D) 25 V , 0 V

Tardigrade Admin · Accepted Answer

At, t=0, switch closes <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/6ce4629ea9e7a74e23adf19b2a46388d-.png" /> Current i=i0[1-e-t R / L] So, at t=0, i=0 So, potential across inductor =25 V and across resistor =0 V

Q. A constant voltage of $25 V$ is applied to a series $L - R$ circuit at $t = 0$ , by closing a switch. What is the potential difference across the resistor and the inductor at time $t = 0$ ?

0 V , 25 V

12.5 V , 1.25 V

10 V , 15 V

25 V , 0 V

At, $t = 0$ , switch closes

Current $i = i_{0} [1 - e^{- tR / L}]$
So, at $t = 0, i = 0$
So, potential across inductor $= 25 V$
and across resistor $= 0 V$

Q. A constant voltage of 25V is applied to a series L−R circuit at t=0, by closing a switch. What is the potential difference across the resistor and the inductor at time t=0 ?