JEE Main 2025 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 3 April 2025, Shift 2, Physics Q39

Question 39 of 75 in this shift, Physics question 14 of 25, Section A.

A motor operating on 100 V draws a current of 1 A. If the efficiency of the motor is 91.6%, then the loss of power in units of cal/s is

(1)6.2
(2)8.4
(3)4
(4)2Official answer

Official answer

Option 4

NTA final key.

Chapter: Current Electricity
Topic: Ohm's Law and Resistance
Idea tested: Joule Heating and Power

Same idea in other shifts

Asked 5× in all

31 Jan 2024, Shift 2 · Q41By what percentage will the illumination of the lamp decrease if the current drops by 20%?EasySingle correct
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16 Mar 2021, Shift 2 · Q18A resistor develops 500 J of thermal energy in 20 s when a current of 1.5A is passed through it. If the current is increased from 1.5 A to…EasySingle correct
16 Mar 2021, Shift 2 · Q28The energy dissipated by a resistor is 10 mJ in 1 s when an electric current of 2 mA flows through it. The resistance is ________ $\Omega$ .…EasyNumerical value

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 42 of the 174 JEE Main shifts held from 2017 to 2026.