Q1 MHT CET 2026 · 19 MAY · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltage is given by V = V 0 sin ( ω t + π 4 ) V = V_0 \sin\left(\omega t + \frac{\pi}{4}\right) V = V 0 sin ( ω t + 4 π ) . The time when the voltage is maximum for the first time is
(T T T = periodic time of the alternating voltage, cos 0 ∘ = sin 9 0 ∘ = 1 \cos 0^\circ = \sin 90^\circ = 1 cos 0 ∘ = sin 9 0 ∘ = 1 )
(a) T 4 \frac{T}{4} 4 T (b) T 6 \frac{T}{6} 6 T (c) T 8 \frac{T}{8} 8 T (d) T 12 \frac{T}{12} 12 T Show answer and solution
Answer: (c)
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Q2 MHT CET 2026 · 15 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An AC source is 120 120 120 V - 60 60 60 Hz. The value of voltage after 1 720 \frac{1}{720} 720 1 s from start will be ( sin 3 0 ∘ = 1 2 ) \left(\sin 30^\circ = \frac{1}{2}\right) ( sin 3 0 ∘ = 2 1 )
(a) 20.2 V 20.2\text{ V} 20.2 V (b) 42.4 V 42.4\text{ V} 42.4 V (c) 84.8 V 84.8\text{ V} 84.8 V (d) 106.9 V 106.9\text{ V} 106.9 V Show answer and solution
Answer: (c)
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Q3 MHT CET 2026 · 14 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltage is E = 100 sin ( ω t + π 6 ) E = 100 \sin\left(\omega t + \frac{\pi}{6}\right) E = 100 sin ( ω t + 6 π ) V. The voltage will be maximum for the first time when t is
( sin π 2 = 1 ) \left(\sin \frac{\pi}{2} = 1\right) ( sin 2 π = 1 ) (T = Periodic time)
(a) T 12 \frac{T}{12} 12 T (b) T 2 \frac{T}{2} 2 T (c) T 6 \frac{T}{6} 6 T (d) T 3 \frac{T}{3} 3 T Show answer and solution
Answer: (c)
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Q4 NEET 2026 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The peak value of an alternating current is 5 A and frequency is 60 Hz. How long will the current, starting from zero, take to reach the peak value?
(a) 1 120 s \frac{1}{120}\text{ s} 120 1 s (b) 1 60 s \frac{1}{60}\text{ s} 60 1 s (c) 1 30 s \frac{1}{30}\text{ s} 30 1 s (d) 1 240 s \frac{1}{240}\text{ s} 240 1 s Show answer and solution
Answer: (d)
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Q5 MHT CET 2026 · 14 MAY · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
A resistance of 20 Ω 20\ \Omega 20 Ω is connected to a source of alternating potential V = 220 sin ( 100 π t ) V = 220 \sin(100\pi t) V = 220 sin ( 100 π t ) . The time taken by current to change from its peak value to r.m.s. value is ( sin π 4 = 1 2 ) \left(\sin \frac{\pi}{4} = \frac{1}{\sqrt{2}}\right) ( sin 4 π = 2 1 )
(a) 0.2 0.2 0.2 s(b) 0.25 0.25 0.25 s(c) 25 × 1 0 − 3 25 \times 10^{-3} 25 × 1 0 − 3 s(d) 2.5 × 1 0 − 3 2.5 \times 10^{-3} 2.5 × 1 0 − 3 sShow answer and solution
Answer: (d)
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Q6 MHT CET 2026 · 16 APR · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating e.m.f. is given by e = e 0 sin ω t e = e_0 \sin \omega t e = e 0 sin ω t . In what time the e.m.f. will have half its maximum value, if 'e' Starts from zero?
(a) T 4 \frac{T}{4} 4 T (b) T 8 \frac{T}{8} 8 T (c) T 12 \frac{T}{12} 12 T (d) T 16 \frac{T}{16} 16 T Show answer and solution
Answer: (c)
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Q7 MHT CET 2026 · 13 APR · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating e.m.f. is given by e = e 0 sin ω t e = e_0 \sin \omega t e = e 0 sin ω t . In what time the e.m.f. will have half its maximum value, if 'e' starts from zero? (sin 3 0 ∘ = 0.5 \sin 30^\circ = 0.5 sin 3 0 ∘ = 0.5 )
(a) T 4 \frac{T}{4} 4 T (b) T 8 \frac{T}{8} 8 T (c) T 12 \frac{T}{12} 12 T (d) T 16 \frac{T}{16} 16 T Show answer and solution
Answer: (c)
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Q8 JEE Main 2026 · 28 JAN · SHIFT 1 Difficult ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
The electric current in the circuit is given as i = i o ( t / T ) i = i_o (t/T) i = i o ( t / T ) . The r.m.s current for the period t = 0 t = 0 t = 0 to t = T t = T t = T is ______ .
(a) i o 2 \frac{i_o}{\sqrt{2}} 2 i o (b) i o 3 \frac{i_o}{\sqrt{3}} 3 i o (c) i o i_o i o (d) i o 6 \frac{i_o}{\sqrt{6}} 6 i o Show answer and solution
Answer: (b)
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Q9 MHT CET 2025 · 19 APR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The instantaneous value of current in an a.c. circuit is I = 3 sin ( 50 π t + π 4 ) A I = 3 \sin\left(50\pi t + \frac{\pi}{4}\right)\text{ A} I = 3 sin ( 50 π t + 4 π ) A . The current will be maximum for the first time at
(a) 1 50 s \frac{1}{50}\text{ s} 50 1 s (b) 1 100 s \frac{1}{100}\text{ s} 100 1 s (c) 1 200 s \frac{1}{200}\text{ s} 200 1 s (d) 1 600 s \frac{1}{600}\text{ s} 600 1 s Show answer and solution
Answer: (c)
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Q10 JEE Main 2025 · 7 APR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An ac current is represented as
i = 5 2 + 10 cos ( 650 π t + π 6 ) Amp i = 5\sqrt{2} + 10 \cos\left(650\pi t + \frac{\pi}{6}\right)\text{ Amp} i = 5 2 + 10 cos ( 650 π t + 6 π ) Amp
The r.m.s value of the current is
(a) 10 Amp (b) 5 2 Amp 5\sqrt{2}\text{ Amp} 5 2 Amp (c) 100 Amp (d) 50 Amp Show answer and solution
Answer: (a)
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Q11 JEE Main 2025 · 4 APR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An alternating current is represented by the equation, i = 100 2 sin ( 100 π t ) i = 100\sqrt{2} \sin(100\pi t) i = 100 2 sin ( 100 π t ) ampere. The RMS value of current and the frequency of the given alternating current are
(a) 100 2 A , 100 Hz \frac{100}{\sqrt{2}}\text{ A}, 100\text{ Hz} 2 100 A , 100 Hz (b) 50 2 A , 50 Hz 50\sqrt{2}\text{ A}, 50\text{ Hz} 50 2 A , 50 Hz (c) 100 2 A , 100 Hz 100\sqrt{2}\text{ A}, 100\text{ Hz} 100 2 A , 100 Hz (d) 100 A , 50 Hz 100\text{ A}, 50\text{ Hz} 100 A , 50 Hz Show answer and solution
Answer: (d)
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Q12 JEE Main 2025 · 3 APR · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An electric bulb rated as 100 W − 220 V 100\text{ W} - 220\text{ V} 100 W − 220 V is connected to an ac source of rms voltage 220 V. The peak value of current through the bulb is:
(a) 0.32 A (b) 0.64 A (c) 0.45 A (d) 2.2 A Show answer and solution
Answer: (b)
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Q13 JEE Main 2025 · 24 JAN · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An alternating current is given by I = I A sin ω t + I B cos ω t I = I_A \sin \omega t + I_B \cos \omega t I = I A sin ω t + I B cos ω t . The r.m.s current will be
(a) I A 2 + I B 2 2 \frac{\sqrt{I_A^2 + I_B^2}}{2} 2 I A 2 + I B 2 (b) I A 2 + I B 2 2 \sqrt{\frac{I_A^2 + I_B^2}{2}} 2 I A 2 + I B 2 (c) ∣ I A + I B ∣ 2 \frac{|I_A + I_B|}{\sqrt{2}} 2 ∣ I A + I B ∣ (d) I A 2 + I B 2 \sqrt{I_A^2 + I_B^2} I A 2 + I B 2 Show answer and solution
Answer: (b)
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Q14 MHT CET 2025 · 22 APR · SHIFT 2 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating e.m.f. is given by e = e 0 sin ω t e = e_0 \sin \omega t e = e 0 sin ω t . In how much time the e.m.f. will have half its maximum value, if e starts from zero?
( T = (T = ( T = Time Period, sin 3 0 ∘ = 1 2 ) \sin 30^\circ = \frac{1}{2}) sin 3 0 ∘ = 2 1 )
(a) T 8 \frac{T}{8} 8 T (b) T 4 \frac{T}{4} 4 T (c) T 12 \frac{T}{12} 12 T (d) T 16 \frac{T}{16} 16 T Show answer and solution
Answer: (c)
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Q15 MHT CET 2024 · 16 MAY · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The alternating voltage is given by v = v 0 sin ( ω t + π 3 ) v = v_0 \sin\left(\omega t + \frac{\pi}{3}\right) v = v 0 sin ( ω t + 3 π ) when will be the voltage maximum for first time?
(a) T 6 \frac{T}{6} 6 T (b) T 3 \frac{T}{3} 3 T (c) T 2 \frac{T}{2} 2 T (d) T 12 \frac{T}{12} 12 T Show answer and solution
Answer: (d)
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Q16 MHT CET 2024 · 4 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating current is given by I = 100 sin ( 50 π t ) I = 100 \sin(50\pi t) I = 100 sin ( 50 π t ) . How many times will the current become zero in one second?
(a) 50 times (b) 25 times (c) 40 times (d) 100 times Show answer and solution
Answer: (a)
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Q17 MHT CET 2024 · 2 MAY · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
In an a.c. circuit I = 100 sin 200 π t I = 100 \sin 200\pi t I = 100 sin 200 π t . The time required for the current to achieve its peak value will be
(a) 1 100 s \frac{1}{100}\text{ s} 100 1 s (b) 1 200 s \frac{1}{200}\text{ s} 200 1 s (c) 1 300 s \frac{1}{300}\text{ s} 300 1 s (d) 1 400 s \frac{1}{400}\text{ s} 400 1 s Show answer and solution
Answer: (d)
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Q18 JEE Main 2024 · 4 APR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An alternating current at any instant is given by i = [ 6 + 56 sin ( 100 π t + π / 3 ) ] i = [6 + \sqrt{56} \sin(100\pi t + \pi/3)] i = [ 6 + 56 sin ( 100 π t + π /3 )] A. The rms value of the current is ______ A.
Numerical answer type. Work it out, then open the answer.
Show answer and solution
Answer: 8
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Q19 JEE Main 2024 · 30 JAN · SHIFT 2 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltage V ( t ) = 220 sin 100 π t V(t) = 220 \sin 100\pi t V ( t ) = 220 sin 100 π t volt is applied to a purely resistive load of 50 Ω 50\ \Omega 50 Ω . The time taken for the current to rise from half of the peak value to the peak value is:
(a) 7.2 ms (b) 3.3 ms (c) 5 ms (d) 2.2 ms Show answer and solution
Answer: (b)
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Q20 MHT CET 2023 · 13 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
A group of lamps having total power rating of 1000 W 1000\text{ W} 1000 W is supplied by an AC voltage of E = 200 sin ( 310 t + 6 0 ∘ ) E = 200 \sin(310t + 60^\circ) E = 200 sin ( 310 t + 6 0 ∘ ) , the rms value of current flowing through the circuit is
(a) 10 A 10\text{ A} 10 A (b) 5 2 A 5\sqrt{2}\text{ A} 5 2 A (c) 20 A 20\text{ A} 20 A (d) 10 2 A 10\sqrt{2}\text{ A} 10 2 A Show answer and solution
Answer: (b)
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Q21 MHT CET 2023 · 11 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
The a.c. source of e.m.f. with instantaneous value 'e e e ' is given by e = 200 sin ( 50 t ) e = 200 \sin(50t) e = 200 sin ( 50 t ) volt. The r.m.s. value of current in a circuit of resistance 50 Ω 50\ \Omega 50 Ω is
(a) 0.2828 A (b) 2.828 A (c) 28.28 A (d) 282.8 A Show answer and solution
Answer: (b)
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Q22 JEE Main 2022 · 27 JUN · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The current flowing through an ac circuit is given by
I = 5 sin(120π \pi π t)A
How long will the current take to reach the peak value starting from zero?
(a) 1 60 \frac{1}{60} 60 1 s(b) 60 s (c) 1 120 \frac{1}{120} 120 1 s(d) 1 240 \frac{1}{240} 240 1 sShow answer and solution
Answer: (d)
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Q23 NEET 2022 · PHASE 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
A standard filament lamp consumes 100 W when connected to 200 V ac mains supply. The peak current through the bulb will be:
(a) 2 A (b) 0.707 A (c) 1 A (d) 1.414 A Show answer and solution
Answer: (b)
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Q24 NEET 2022 · PHASE 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
The peak voltage of the ac source is equal to
(a) The value of voltage supplied to the circuit (b) The rms value of the ac source (c) 2 \sqrt{2} 2 times the rms value of the ac source(d) 1/ 2 \sqrt{2} 2 times the rms value of the ac source Show answer and solution
Answer: (c)
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Q25 JEE Main 2022 · 27 JUL · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
A direct current of 4 A 4\text{ A} 4 A and an alternating current of peak value 4 A 4\text{ A} 4 A flow through resistance of 3 Ω 3\ \Omega 3 Ω and 2 Ω 2\ \Omega 2 Ω respectively. The ratio of heat produced in the two resistances in same interval of time will be:
(a) 3: 2 (b) 3: 1 (c) 3: 4 (d) 4: 3 Show answer and solution
Answer: (b)
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Q26 MHT CET 2022 · 11 AUG · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · AC meters, waveforms and skin effect
In a full wave rectifier circuit without filter, the output current is
(a) an eddy current (b) a constant direct current (c) a sinusoidal current (d) unidirectional but not steady current Show answer and solution
Answer: (d)
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Q27 JEE Main 2022 · 24 JUN · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
A resistance of 40 Ω \Omega Ω is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to the rms value:
(a) 2.5 ms (b) 1.25 ms (c) 2.5 s (d) 0.25 s Show answer and solution
Answer: (a)
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Q28 JEE Main 2022 · 27 JUN · SHIFT 1 Difficult ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
A 220 V, 50 Hz AC source is connected to a 25 V, 5 W lamp and an additional resistance R in series (as shown in figure) to run the lamp at its peak brightness, then the value of R (in ohm) will be _____________.
Numerical answer type. Work it out, then open the answer.
Show answer and solution
Answer: 975
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Q29 MHT CET 2021 · 24 SEP · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The peak value of an alternating emf 'e e e ' given by e = e 0 cos ω t e = e_0 \cos \omega t e = e 0 cos ω t is 10 volt and its frequency is 50 Hz 50\text{ Hz} 50 Hz . At time t = 1 600 s t = \frac{1}{600}\text{ s} t = 600 1 s , the instantaneous e.m.f is ( cos π 6 = sin π 3 = 3 2 ) \left(\cos \frac{\pi}{6} = \sin \frac{\pi}{3} = \frac{\sqrt{3}}{2}\right) ( cos 6 π = sin 3 π = 2 3 )
(a) 10 V 10\text{ V} 10 V (b) 1 3 V \frac{1}{\sqrt{3}}\text{ V} 3 1 V (c) 5 V 5\text{ V} 5 V (d) 5 3 V 5\sqrt{3}\text{ V} 5 3 V Show answer and solution
Answer: (d)
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Q30 MHT CET 2021 · 21 SEP · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltge is represented by V = 80 sin ( 100 π t ) cos ( 100 π t ) V = 80 \sin(100\pi t) \cos(100\pi t) V = 80 sin ( 100 π t ) cos ( 100 π t ) volt. The peak voltage is
(a) 20 V 20\text{ V} 20 V (b) 40 V 40\text{ V} 40 V (c) 30 V 30\text{ V} 30 V (d) 50 V 50\text{ V} 50 V Show answer and solution
Answer: (b)
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Q31 JEE Main 2021 · 18 MAR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to the rms value is:
(a) 2.5 ms (b) 25 ms (c) 2.5 s (d) 0.25 ms Show answer and solution
Answer: (a)
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Q32 MHT CET 2021 · 24 SEP · SHIFT 2 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating e.m.f. is e = e 0 sin ω t e = e_0 \sin \omega t e = e 0 sin ω t . In what time the e.m.f. will have half its maximum value, if 'e e e ' starts from zero? (T = T = T = time period, sin 3 0 ∘ = 0.5 \sin 30^\circ = 0.5 sin 3 0 ∘ = 0.5 )
(a) T 12 \frac{T}{12} 12 T (b) T 16 \frac{T}{16} 16 T (c) T 4 \frac{T}{4} 4 T (d) T 8 \frac{T}{8} 8 T Show answer and solution
Answer: (a)
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Q33 MHT CET 2021 · 21 SEP · SHIFT 2 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
The instantaneous value of an alternating current is given by i = 50 sin ( 100 π t ) i = 50 \sin(100\pi t) i = 50 sin ( 100 π t ) . It will achieve a value of 25 A 25\text{ A} 25 A after a time interval of ( sin 3 0 ∘ = 0.5 ) (\sin 30^\circ = 0.5) ( sin 3 0 ∘ = 0.5 )
(a) 1 300 s \frac{1}{300}\text{ s} 300 1 s (b) 1 100 s \frac{1}{100}\text{ s} 100 1 s (c) 1 200 s \frac{1}{200}\text{ s} 200 1 s (d) 1 600 s \frac{1}{600}\text{ s} 600 1 s Show answer and solution
Answer: (d)
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Q34 JEE Main 2021 · 25 JUL · SHIFT 2 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
A 10 Ω \Omega Ω resistance is connected across 220V − - − 50 Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:
(a) 2.5 ms (b) 1.5 ms (c) 3.0 ms (d) 4.5 ms Show answer and solution
Answer: (a)
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Q35 JEE Main 2021 · 17 MAR · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An AC current is given by I = I1 sinω \omega ω t + I2 cosω \omega ω t. A hot wire ammeter will give a reading:
(a) I 1 + I 2 2 \frac{I_1 + I_2}{\sqrt{2}} 2 I 1 + I 2 (b) I 1 2 − I 2 2 2 \sqrt{\frac{I_1^2 - I_2^2}{2}} 2 I 1 2 − I 2 2 (c) I 1 2 + I 2 2 2 \sqrt{\frac{I_1^2 + I_2^2}{2}} 2 I 1 2 + I 2 2 (d) I 1 + I 2 2 2 \frac{I_1 + I_2}{2\sqrt{2}} 2 2 I 1 + I 2 Show answer and solution
Answer: (c)
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Q36 JEE Main 2021 · 26 FEB · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
An alternating current is given by the equation i = i1 sin ω \omega ω t + i2 cos ω \omega ω t. The rms current will be:
(a) 1 2 ( i 1 2 + i 2 2 ) 1 2 \frac{1}{\sqrt{2}}\left(i_1^2 + i_2^2\right)^{\frac{1}{2}} 2 1 ( i 1 2 + i 2 2 ) 2 1 (b) 1 2 ( i 1 + i 2 ) \frac{1}{\sqrt{2}}(i_1 + i_2) 2 1 ( i 1 + i 2 ) (c) 1 2 ( i 1 + i 2 ) 2 \frac{1}{\sqrt{2}}(i_1 + i_2)^2 2 1 ( i 1 + i 2 ) 2 (d) 1 2 ( i 1 2 + i 2 2 ) 1 2 \frac{1}{2}\left(i_1^2 + i_2^2\right)^{\frac{1}{2}} 2 1 ( i 1 2 + i 2 2 ) 2 1 Show answer and solution
Answer: (a)
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Q37 JEE Main 2021 · 27 AUG · SHIFT 1 Difficult ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
The alternating current is given by i = { 42 sin ( 2 π T t ) + 10 } A i = \left\{\sqrt{42} \sin\left(\frac{2\pi}{T} t\right) + 10\right\} A i = { 42 sin ( T 2 π t ) + 10 } A
The r.m.s. value of of this current is ................. A.
Numerical answer type. Work it out, then open the answer.
Show answer and solution
Answer: 11
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Q38 MHT CET 2019 · 2 MAY · SHIFT 2 Easy ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltage is given by E = 100 sin ( ω t + π 6 ) V E = 100 \sin\left(\omega t + \frac{\pi}{6}\right)\text{ V} E = 100 sin ( ω t + 6 π ) V . The voltage will be maximum for the first time when is [ T = T = T = periodic time)
(a) T 12 \frac{T}{12} 12 T (b) T 2 \frac{T}{2} 2 T (c) T 6 \frac{T}{6} 6 T (d) T 3 \frac{T}{3} 3 T Show answer and solution
Answer: (c)
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Q39 NEET 2019 Easy ☆
AC Basics: Peak, RMS & Average Values · AC meters, waveforms and skin effect
The variation of EMF with time for four types of generators are shown in the figures. Which amongst them can be called AC?
(a) Only (a) (b) (a) and (d) (c) (a), (b), (c), (d) (d) (a) and (b) Show answer and solution
Answer: (c)
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Q40 JEE Main 2019 · 8 APR · SHIFT 1 Medium ☆
AC Basics: Peak, RMS & Average Values · Equation, instantaneous value and time
An alternating voltage v(t) = 220 sin 100 π \pi π t volt is applied to a purely resistance load of 50Ω \Omega Ω . The time taken for the current to rise from half of the peak value to the peak value is:
(a) 5 ms (b) 2.2 ms (c) 3.3 ms (d) 7.2 ms Show answer and solution
Answer: (c)
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Q41 JEE Main 2015 · 11 APR · SHIFT 1 Easy ☆
AC Basics: Peak, RMS & Average Values · AC meters, waveforms and skin effect
The AC voltage across a resistance can be measured using a:
(a) potentiometer (b) moving coil galvanometer (c) moving magnet galvanometer (d) hot wire voltmeter Show answer and solution
Answer: (d)
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Q42 NEET 2011 · AIPMT · MAINS Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
The r.m.s. value of potential difference V shown in the figure is
(a) V 0 3 \frac{V_0}{\sqrt{3}} 3 V 0 (b) V0 (c) V 0 2 \frac{V_0}{\sqrt{2}} 2 V 0 (d) V 0 2 \frac{V_0}{2} 2 V 0 Show answer and solution
Answer: (c)
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Q43 JEE Main 2004 · AIEEE Easy ☆
AC Basics: Peak, RMS & Average Values · AC meters, waveforms and skin effect
Alternating current can not be measured by D.C. \text{D.C.} D.C. ammeter because
(a) Average value of current for complete cycle is zero (b) A.C. \text{A.C.} A.C. Changes direction(c) A.C. \text{A.C.} A.C. can not pass through D.C. \text{D.C.} D.C. Ammeter(d) D.C. \text{D.C.} D.C. Ammeter will get damaged.Show answer and solution
Answer: (a)
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Q44 NEET 1994 · AIPMT Easy ☆
AC Basics: Peak, RMS & Average Values · Peak, RMS and average values
In an A.C. circuit, I rms I_{\text{rms}} I rms and I 0 I_0 I 0 are related as
(a) I rms = π I 0 I_{\text{rms}} = \pi I_0 I rms = π I 0 (b) I rms = 2 I 0 I_{\text{rms}} = \sqrt{2}\, I_0 I rms = 2 I 0 (c) I rms = I 0 / π I_{\text{rms}} = I_0/\pi I rms = I 0 / π (d) I rms = I 0 / 2 I_{\text{rms}} = I_0/\sqrt{2} I rms = I 0 / 2 Show answer and solution
Answer: (d)
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Q45 NEET 1994 · AIPMT Easy Old syllabus ☆
AC Basics: Peak, RMS & Average Values · AC meters, waveforms and skin effect
Two cables of copper are of equal lengths. One of them has a single wire of area of cross-section A A A , while other has 10 wires of cross-sectional area A / 10 A/10 A /10 each. Give their suitability for transporting A.C. and D.C.
(a) only multiple strands for A.C., either for D.C. (b) only multiple strands for A.C., only single strand for D.C. (c) only single strand for D.C., either for A.C. (d) only single strand for A.C., either for D.C. Show answer and solution
Answer: (a)
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