Verified Solution • 2025–26 Session moderate

QJEEM23Phea35: JEE Main 2023 Physics - Class 12 JEEM23Phea35 Solution: A small object at rest, absorbs a light pulse of power and…

A small object at rest, absorbs a light pulse of power 20 mW20 \mathrm{~mW} and duration 300 ns300 \mathrm{~ns} . Assuming speed of light as 3×108 m/s3 \times 10^{8} \mathrm{~m} / \mathrm{s} , the momentum of the object becomes equal to :

Multiple Choice Options

  • A 1×10−17 kg m/s1 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}
  • B 0.5×10−17 kg m/s0.5 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}
  • C 3×10−17 kg m/s3 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}
  • D 2×10−17 kg m/s2 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}

Step-by-Step Verified Solution

Assuming the small object as photon.

Momentum (p)=EC(p)=\frac{E}{C}

=20×10−3×300×10−93×108=\frac{20\times10^{-3}\times300\times10^{-9}}{3\times10^8}

=2×10−17=2\times10^{-17} kg m/s

Related Learning Resources & Exam Preparation

JEE Main PYQ Question Bank
Browse year-wise authentic previous years' questions with solutions
Authentic CBT Mock Tests
Simulate official exam environment with live timer and percentile scoring