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Alternating Quantities: RMS and Mean for JEE: 17 solved questions

Real JEE paper questions on alternating quantities: rms and mean, part of alternating current. Each opens with the options, the correct answer and a step-by-step solution. Papers run from 2004 to 2026. No sign-in needed to read them.

What this topic asks

• RMS and mean values — 9 questions
• Instantaneous values and timing — 5 questions
• Measuring AC quantities — 3 questions

All 17 questions with solutions

• The current in a circuit is i=i₀(t/T). The r.m.s. current over the period t=0 to t=T is JEE Main 28th Jan 1st Shift 2026
• An electric bulb rated 100 W--220 V is connected to an a.c. source of r.m.s. voltage 220 V. The peak value of… JEE Main 3rd April 2nd Shift 2025
• An alternating current is i=100√2 sin(100π t) A. The r.m.s. value of the current and the frequency are JEE Main 4th April 1st Shift 2025
• An a.c. current is i=5√2+10 cos (650π t+π/6) A. The r.m.s. value of the current is JEE Main 7th April 1st Shift 2025
• An alternating current is I=I_A sin ω t+I_B cos ω t. The r.m.s. current is JEE Main 24th Jan 1st Shift 2025
• An alternating voltage V(t)=220 sin(100π t) V is applied to a purely resistive load of 50 Ω. The time taken f… JEE Main 30th Jan 2nd Shift 2024 (also JEE Main 8th April 1st Shift 2019)
• A direct current of 4 A flows through a 3 Ω resistance and an alternating current of peak value 4 A flows thr… JEE Main 27th July 1st Shift 2022
• A 40 Ω resistance is connected to an a.c. source rated 220 V, 50 Hz. The time taken by the current to change… JEE Main 24th June 1st Shift 2022
• The current in an a.c. circuit is I=5 sin(120π t) A. The time taken by the current to reach its peak value st… JEE Main 27th June 1st Shift 2022
• A 10 Ω resistance is connected across a 220 V--50 Hz a.c. supply. The time taken by the current to change fro… JEE Main 25th July 2nd Shift 2021
• An a.c. current is I=I₁ sin ω t+I₂ cos ω t. A hot-wire ammeter reads JEE Main 17th March 1st Shift 2021
• An a.c. source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from it… JEE Main 18th March 1st Shift 2021
• An alternating current is i=i₁ sin ω t+i₂ cos ω t. The r.m.s. value is JEE Main 26th Feb 1st Shift 2021
• The a.c. voltage across a resistance can be measured using a JEE Main Online 2015
• Alternating current cannot be measured by a D.C. ammeter because AIEEE 2004
• An alternating current is i=[6+√56 sin (100π t+π/3)] A. The r.m.s. value of the current is A. JEE Main 4th April 1st Shift 2024
• The alternating current is i={√42 sin ((2π)/Tt)+10} A. The r.m.s. value of this current is A. JEE Main 27th Aug 1st Shift 2021