The $\text{RMS}$ value of a rectangular wave of period $T$, having a value of $+V$ for a duration, $T_1(<T)$ and $-V$ for the duration, $T-T_1=T_2$, equals
- $\mathrm{V}$
- $\frac{\mathrm{T}_1-\mathrm{T}_2}{\mathrm{~T}} \mathrm{~V}$
- $\frac{\mathrm{V}}{\sqrt{2}}$
- $\frac{\mathrm{T}_1}{\mathrm{~T}_2} \mathrm{~V}$