A resistance of \( 40\,\Omega \) is connected to an a.c. source of \( 220\,\mathrm{V} \), \( 50\,\mathrm{Hz} \). The rms current in the circuit is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 5.5\,\mathrm{A} \)
The voltage of an a.c. supply is quoted as its rms value, and for a pure resistor the rms current follows Ohm’s law directly; the frequency does not affect a resistor.
\( I_{\mathrm{rms}} = \frac{V_{\mathrm{rms}}}{R} = \frac{220\,\mathrm{V}}{40\,\Omega} = 5.5\,\mathrm{A} \)
Note: NTA picked this question from an NCERT (2026-27) exercise and changed the figures. Do not ignore NCERT while practising numericals.
NCERT (2026-27):
Exercises – …
