GATE EE 2017 Set 1 — Question 41
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.MCQ+2 / -0.67MediumFirst-Order RL & RCTransient & AC Steady-StateElectric Circuits
Electric Circuits → Transient & AC Steady-State → First-Order RL & RC
Last updated
Question
The switch in the figure below was closed for a long time. It is opened at . The current in the inductor of for , is

Correct answer
(A) 2.5e^(-4t)
Solution
1.Initial State ():
The switch is closed and the circuit is in steady state. The inductor acts as a short circuit. The bridge consists of resistors , , , , and a diagonal resistor .
With the inductor shorting the rightmost resistor, the equivalent resistance of the bridge is calculated. For the given values, the initial current through the inductor is found to be .
2.Transient State ():
The switch is opened, disconnecting the source and the resistor. The inductor discharges through the bridge resistors.The equivalent resistance seen by the inductor terminals is calculated. For this circuit, .
The time constant is .
3.Current Expression:
The current for is given by:Thus, the correct option is (A).
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE EE question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Transient & AC Steady-State
2026 Set 1 Q23A circuit with ideal elements is shown. [figure] Which one of the following options correctly…2026 Set 1 Q24For the circuit shown, which one of the following options correctly identifies the Thevenin’s…2026 Set 1 Q25Refer to the four circuits shown. Which one of the following options for and …2026 Set 1 Q26A single-phase voltage source V delivers a current,…2026 Set 1 Q42An electrical component has voltage drop , when the current through it is…