Q. The dimension $[M L^{- 1} T^{- 2}]$ represents

1438 217 Punjab PMETPunjab PMET 2001Physical World, Units and Measurements Report Error

A

Youngs modulus

9%

B

stress

11%

C

pressure

21%

D

all of these

59%

Solution:

The dimensional formula of Young's modulus
$Y = \frac{F / A}{Δ l / l} = \frac{[ M L T ^{- 2} ]}{[ L ^{2} ]}$
$= [M L^{- 1} T^{- 2}]$
The dimensional formula of stress
$= \frac{F}{A} = \frac{[ M L T ^{- 2} ]}{[ L ^{2} ]}$
$= [M L^{- 1} T^{- 2}]$
Hence, all of these are represented by
$[M L^{- 1} T^{- 2}]$