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Saturday, 31 October

JEE Main 2020 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 5 September 2020, Shift 1, Physics Q6

Question 6 of 75 in this shift, Physics question 6 of 25.

A bullet of mass 5 g, travelling with a speed of 210 m/s, strikes a fixed wooden target. One half of its kinetic energy is converted into heat in the bullet while the other half is converted into heat in the wood. The rise of temperature of the bullet if the specific heat of its material is 0.030 cal/(g −- °C) (1 cal = 4.2×1074.2\times10^7 ergs) close to :
  1. (1)119.2°C
  2. (2)38.4°C
  3. (3)87.5°COfficial answer
  4. (4)83.3°C

Official answer

Option 3

NTA final key (Sep 2020).

Chapter
Thermal Properties of Matter
Topic
Calorimetry
Idea tested
Mechanical Equivalent of Heat

Same idea in other shifts

Asked 3× in all
  1. 8 Apr 2025, Shift 2 · Q32Water falls from a height of 200 m into a pool. Calculate the rise in temperature of the water assuming no heat dissipation from the water…EasySingle correct
  2. 24 Jun 2022, Shift 2 · Q44A 100 g of iron nail is hit by a 1.5 kg hammer striking at a velocity of 60 ms−1ms^{-1}. What will be the rise in the temperature of the…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.