JEE MAIN - Physics (2023 - 25th January Evening Shift - No. 13)

Match List I with List II

List I List II
A. Young's Modulus (Y) I. $$\mathrm{[ML^{-1}T^{-1}]}$$
B. Co-efficient of Viscosity ($$\eta$$) II. $$\mathrm{[ML^2T^{-1}]}$$
C. Planck's Constant (h) III. $$\mathrm{[ML^{-1}T^{-2}]}$$
D. Work function ($$\varphi $$) IV. $$\mathrm{[ML^2T^{-2}]}$$

Choose the correct answer from the options given below :

A-II, B-III, C-IV, D-I
A-I, B-II, C-III, D-IV
A-I, B-III, C-IV, D-II
A-III, B-I, C-II, D-IV

Explanation

$$ \begin{aligned} & \mathrm{Y}=\frac{\text { Stress }}{\text { Strain }}=\frac{\mathrm{F} / \mathrm{A}}{\Delta \ell / \ell}=\frac{\left[\mathrm{MLT}^{-2}\right]}{\left[\mathrm{L}^2\right]}=\left[\mathrm{ML}^{-1} \mathrm{~T}^{-2}\right] \\\\ & \mathrm{F}=6 \pi \eta \mathrm{rv} \Rightarrow \eta=\frac{\mathrm{F}}{6 \pi \mathrm{rv}} \\\\ & {[\eta]=\frac{\left[\mathrm{MLT}^{-2}\right]}{[\mathrm{L}]\left[\mathrm{LT}^{-1}\right]}=\left[\mathrm{ML}^{-1} \mathrm{~T}^{-1}\right]} \\\\ & \mathrm{E}=\mathrm{h} v \Rightarrow \mathrm{h}=\frac{\mathrm{E}}{v}=\frac{\left[\mathrm{ML}^2 \mathrm{~T}^{-2}\right]}{\left[\mathrm{T}^{-1}\right]}=\left[\mathrm{ML}^2 \mathrm{~T}^{-1}\right] \end{aligned} $$

Work function has same dimension as that of energy, so $[\phi]=\left[\mathrm{ML}^2 \mathrm{~T}^{-2}\right]$

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