A peak current of 2 A flows through a resistive ac circuit. What is t…

The correct answer is Option (1) → \( 1.41\,\mathrm{A} \)

For a sinusoidal current the rms (effective) value is related to the peak value by \( I=i_m/\sqrt{2} \). Here the peak current is \( i_m=2\,\mathrm{A} \).

    \( \begin{aligned} I &= \frac{i_m}{\sqrt{2}} \\ &= \frac{2\,\mathrm{A}}{\sqrt{2}} \\ &\approx 1.41\,\mathrm{A} \end{aligned} \)

NCERT (2026-27):
AC Voltage Applied to a Resistor – “To express ac power in the same form as dc power (P = I²R), a special value of current is defined and used. It is called, root mean square (rms) or effective current … and is denoted by I_rms or I. … It is defined by

    \( \displaystyle I=\sqrt{\overline{i^{2}}}=\sqrt{\frac{1}{2}\,i_m^{2}}=\frac{i_m}{\sqrt{2}}=0.707\,i_m \)\( \qquad (7.6) \)”