PYQ NEET- Units Of Measurement L-7

Plane angle and solid angle have dimensions of radians and steradians respectively#

A) Units but no dimensions

B) Dimensions without units

C) No units and no dimensions

D) Both units and dimensions

Answer: Both units and dimensions#

Solution:#

Plane angle $=\frac{A r c}{\text { Radius }}=\frac{[L]}{[L]} \longrightarrow$ Unit $=$ Radian

$=\left[M^0 L^0 T^0\right]$

Solid angle $=\frac{\text { Area }}{(\text { Radius })^2} \longrightarrow$ Unit $=$ Steradian

$=\frac{L^2}{L^2}=\left[M^0 L^0 T^0\right]$

$\therefore$ Both have units but no dimension.