GATE EE 2026 Set 1 — Question 33
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.NAT+1 / -0MediumZener RegulatorDiode CircuitsAnalog & Digital Electronics
Analog & Digital Electronics → Diode Circuits → Zener Regulator
Last updated
Question
In the linear regulator circuit shown, the base to emitter voltage of the BJT is . The Zener diode clamps the base voltage to . Ignore the biasing current of the Zener diode and BJT.The maximum possible efficiency of the regulator circuit is ___________ % (Round off to one decimal place)
Correct answer
47.5 to 48
Solution
1.Output voltage: The Zener diode holds the base at , so the emitter (output) voltage is
2.Output power: With ,
3.Input power: Ignoring the base current, the transistor's collector current equals its emitter current, , drawn from the source. Since the Zener and base bias currents are to be ignored, the input current is just :
This is the maximum possible efficiency, since any bias current only adds to the input power.4.Effect of the bias resistor: Strictly, the resistor carries . Including it gives and . Because the question says to ignore the bias currents, both readings are accepted, so any value from to is correct.
Answer: 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 Diode Circuits
2026 Set 1 Q37In the circuit shown, the open loop gain of the operational amplifier is . What is the…2026 Set 1 Q45The digital circuit shown has 3 inputs (, , and ). [figure] The simplified logical…2026 Set 1 Q46The MOSFET switches shown in the circuit are ideal. [figure] Which of the following is the correct…2026 Set 1 Q61Consider the circuit shown. Assume that the diode () is ideal. Given …2025 Set 1 Q16Which one of the following statements is true about the small signal voltage gain of a MOSFET based…