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JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 26 August 2021, Shift 1, Physics Q10

Question 10 of 90 in this shift, Physics question 10 of 30, Section A.

A series LCR circuit driven by 300 V at a frequency of 50 Hz contains a resistance R=3 k

\Omega

, an inductor of inductive reactance

X_L=250\pi\ \Omega

and an unknown capacitor. The value of capacitance to maximize the average power should be : (take

\pi^2=10

)

(1)400 $\mu$ F
(2)40 $\mu$ F
(3)25 $\mu$ F
(4)4 $\mu$ FOfficial answer

Official answer

Option 4

NTA final key.

Chapter: Alternating Current
Topic: LCR Resonance
Idea tested: Resonance Condition

Same idea in other shifts

Asked 2× in all

25 Jul 2022, Shift 2 · Q40When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on :EasySingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.