Learn

Saturday, 31 October

JEE Main 2022 · PhysicsMultiple choiceOtherMediumApplication

JEE Main 27 July 2022, Shift 1, Physics Q38

Question 38 of 90 in this shift, Physics question 8 of 30, Section A.

Read the following statements : A. When small temperature difference between a liquid and its surrounding is doubled, the rate of loss of heat of the liquid becomes twice. B. Two bodies P and Q having equal surface areas are maintained at temperature 10°C and 20°C. The thermal radiation emitted in a given time by P and Q are in the ratio 1:1.15. C. A Carnot Engine working between 100K and 400K has an efficiency of 75%. D. When small temperature difference between a liquid and its surrounding is quadrupled, the rate of loss of heat of the liquid becomes twice. Choose the correct answer from the options given below :
  1. (1)A, B, C onlyOfficial answer
  2. (2)A, B only
  3. (3)A, C only
  4. (4)B, C, D only

Official answer

Option 1

NTA final key.

Chapter
Thermal Properties of Matter
Topic
Thermal Radiation
Idea tested
Newton's Law of Cooling

Same idea in other shifts

Asked 3× in all
  1. 6 Apr 2023, Shift 2 · Q38A body cools in 7 minutes from 60∘60^\circC to 40∘40^\circC. The temperature of the surrounding is 10∘10^\circC. The temperature of the body…MediumSingle correct
  2. 22 Jul 2021, Shift 2 · Q23In 5 minutes, a body cools from 75°C to 65°C at room temperature of 25°C. The temperature of body at the end of next 5 minutes is ________…MediumNumerical 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 108 of the 174 JEE Main shifts held from 2017 to 2026.