Match List - I with List - II. Choose the most appropriate answer from the options given below: List - I List - II (a) RH (Rydberg constant) (i) kg m⁻¹ s⁻¹ (b) h (Planck's constant) (ii) kg m² s⁻¹ (c) μB (Magnetic field energy density) (iii) m⁻¹ (d) η (coefficient of viscocity) (iv) kg m⁻¹ s⁻² (a) (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i) (b) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i) (c) (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii) (d) (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)

Answer: (b). Rydberg constant: (1)/(λ) = RH((1)/(n₁²) - (1)/(n₂²)), so RH is in m ⁻¹ → (iii). h = J s = kg m ² s ⁻¹ → (ii). Magnetic energy density (B²)/(2μ₀) = J m ⁻³ = kg m ⁻¹ s ⁻² → (iv). Viscosity = Pa s = kg m ⁻¹ s ⁻¹ → (i). So the answer is (b) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i).

Match List - I with List - II. Choose the most appropriate answer… | JEE Main 2021 (27 Aug, Shift 2)

Q63JEE Main 2021 · 27 AUG · SHIFT 2Medium

Units & Dimensions

Match List - I with List - II.

Choose the most appropriate answer from the options given below:

	List - I		List - II
(a)	$R_H$ (Rydberg constant)	(i)	$\text{kg m}^{-1}\text{ s}^{-1}$
(b)	h (Planck's constant)	(ii)	$\text{kg m}^{2}\text{ s}^{-1}$
(c)	$\mu_B$ (Magnetic field energy density)	(iii)	$\text{m}^{-1}$
(d)	$\eta$ (coefficient of viscocity)	(iv)	$\text{kg m}^{-1}\text{ s}^{-2}$

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Answer: (b)

Rydberg constant: $\dfrac{1}{\lambda} = R_H\left(\dfrac{1}{n_1^2} - \dfrac{1}{n_2^2}\right)$ , so $R_H$ is in m $^{-1}$ → (iii).
$h$ = J s = kg m $^2$ s $^{-1}$ → (ii).
Magnetic energy density $\dfrac{B^2}{2\mu_0}$ = J m $^{-3}$ = kg m $^{-1}$ s $^{-2}$ → (iv).
Viscosity = Pa s = kg m $^{-1}$ s $^{-1}$ → (i).
So the answer is (b) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i).

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