Physics · Newton's Laws of Motion

JEE Main 2024 — 6 April, Shift 1 — Question 45

A light string passing over a smooth light pulley connects two blocks of masses m1\mathrm{m}_{1} and m2\mathrm{m}_{2} (where m2>m1\mathrm{m}_{2}>\mathrm{m}_{1} ). If the acceleration of the system is g2\frac{\mathrm{g}}{\sqrt{2}}, then the ratio of the masses m1 m2\frac{\mathrm{m}_{1}}{\mathrm{~m}_{2}} is :

  1. Option A:

    2−12+1\frac{\sqrt{2}-1}{\sqrt{2}+1}

    Correct
  2. Option B:

    1+55−1\frac{1+\sqrt{5}}{\sqrt{5}-1}

  3. Option C:

    1+52−1\frac{1+\sqrt{5}}{\sqrt{2}-1}

  4. Option D:

    3+12−1\frac{\sqrt{3}+1}{\sqrt{2}-1}

Answer: A

Step-by-step solution

a=(M2−M1M1+M2)ga=\left(\frac{M_{2}-M_{1}}{M_{1}+M_{2}}\right) g

g2=(M2−M1M1+M2)g\frac{g}{\sqrt{2}}=\left(\frac{M_{2}-M_{1}}{M_{1}+M_{2}}\right) g (M1+M2)=2M2−2M1\left(M_{1}+M_{2}\right)=\sqrt{2} M_{2}-\sqrt{2} M_{1} M1M2=(2−12+1)\frac{\mathrm{M}_{1}}{\mathrm{M}_{2}}=\left(\frac{\sqrt{2}-1}{\sqrt{2}+1}\right)

Solution figure

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Physics
Chapter
Newton's Laws of Motion
Topic
Pulley - Block Problems