Question

Few quantities with their units are listed below. Mark the units which are not correctly matched.
(i) Density : kg $m^{-3}$
(ii) Velocity of light : m $s^{-1}$
(iii) Planck's constant : $J^{-1}{s}^{-1}$
(iv) Acceleration : m $s^{-2}$
(v) Force : kg m

• A. (ii) and (iv)
• B. (i) and (iii)
• C. (iii) and (v)
• D. (iv) and (v)

Answer 1

Answer: (C)

(iii) and (v)

(i) Density : mass per unit volume, unit: $kg{m}^{-3}$

(ii) Velocity of light: distance per unit time, unit: $m{s}^{-1}$

(iii) Planck's constant: Energy $\times$ time, unit:$Js$

(iv)Acceleration: rate of change of velocity, unit $m{s}^{-2}$

(v)Force: mass $\times$ acceleration, unit: $kgm{s}^{-2}$

Thus (iii) and (v) donot match

option C is correct