Q72 / 75 · JEE Main 2025 (28 Jan Shift 1) · Physics
In a measurement, it is asked to find modulus of elasticity per unit torque applied on the system. The measured quantity has dimension of $\left[M^a L^b T^c\right]$. If $b=-3$, the value of $c$ is ________
Correct answer: 0
Solution
[Modulus of elasticity] $=\mathrm{ML}^{-1} \mathrm{~T}^{-2}$
[Torque] $=$ ML $^2 \mathrm{~T}^{-2}$
[Modulus of elasticity per unit torque]
$=\frac{\mathrm{ML}^{-1} \mathrm{~T}^{-2}}{\mathrm{ML}^2 \mathrm{~T}^{-2}}=\mathrm{L}^{-3}$
Hence, the correct answer is 0.