Question:
Which of the following is not a dimensionless quantity ?
Correct Option: , 3
Solution:
$\left[\mu_{r}\right]=1$ as $\mu_{\Gamma}=\frac{\mu}{\mu_{m}}$
$[$ power factor $(\cos \phi)]=1$
$\mu_{0}=\frac{\mathrm{B}_{0}}{\mathrm{H}}\left(\right.$ unit $\left.=\mathrm{NA}^{-2}\right):$ Not dimensionless
$\left[\mu_{0}\right]=\left[\mathrm{MLT}^{-2} \mathrm{~A}^{-2}\right]$
quality factor $(\mathrm{Q})=\frac{\text { Energy stored }}{\text { Energy dissipated per cycle }}$
So $\mathrm{Q}$ is unitless \& dimensionless.