JEE Main 2024 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 30 January 2024, Shift 1, Physics Q43

Question 43 of 90 in this shift, Physics question 13 of 30, Section A.

A series L.R circuit connected with an ac source

E = (25\sin 1000\,t)

V has a power factor of

\frac{1}{\sqrt{2}}

. If the source of emf is changed to

E = (20\sin 2000\,t)

V, the new power factor of the circuit will be :

(1) $\frac{1}{\sqrt{2}}$
(2) $\frac{1}{\sqrt{3}}$
(3) $\frac{1}{\sqrt{5}}$ Official answer
(4) $\frac{1}{\sqrt{7}}$

Official answer

Option 3

NTA final key.

Chapter: Alternating Current
Topic: Phasor Diagrams
Idea tested: Power Factor from Phasors

Same idea in other shifts

Asked 9× in all

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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.