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Friday, 9 October

JEE Main 2025 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 3 April 2025, Shift 1, Physics Q40

Question 40 of 75 in this shift, Physics question 15 of 25, Section A.

The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2m away from it, is
  1. (1)3×10−83 \times 10^{-8} Pascals
  2. (2)6×10−86 \times 10^{-8} PascalsOfficial answer
  3. (3)1.5×10−81.5 \times 10^{-8} Pascals
  4. (4)0

Official answer

Option 2

NTA final key.

Chapter
Electromagnetic Waves
Topic
Thermal Radiation
Idea tested
Thermal Radiation Pressure

Same idea in other shifts

Asked 2× in all
  1. 8 Apr 2024, Shift 1 · Q42Average force exerted on a non-reflecting surface at normal incidence is 2.4×10−42.4\times10^{-4} N. If 360 W/cm2^2 is the light energy flux…MediumSingle 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 42 of the 174 JEE Main shifts held from 2017 to 2026.