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JEE Main 20257 AprilMorning Shift
Exam
JEE Main
Year
2025
Date
7 April
Shift
Morning Shift
Subject
Physics
Chapter
Alternating Current

JEE Main 2025 · 7 April · Morning Shift · Physics · Alternating Current

An ac current is represented as i=5 2 +10 (650 π t+(π)/(6)) Amp The...

An ac current is represented as
i=52+10cos⁡(650πt+π6)Amp\mathrm{i}=5 \sqrt{2}+10 \cos \left(650 \pi \mathrm{t}+\frac{\pi}{6}\right) \mathrm{Amp}
The r.m.s value of the current is

Options

  1. A50 Amp
  2. B100 Amp
  3. C10 Amp
  4. D52Amp5 \sqrt{2} \mathrm{Amp}

Correct answer

C. 10 Amp

Step-by-step solution

i=52+10cos⁡(650πt+π6)i=5 \sqrt{2}+10 \cos \left(650 \pi t+\frac{\pi}{6}\right)
i2=50+100cos⁡2(650πt+π6)\mathrm{i}^2=50+100 \cos ^2\left(650 \pi \mathrm{t}+\frac{\pi}{6}\right)
+(2)(52)(10)cos⁡(650πt+π6)+(2)(5 \sqrt{2})(10) \cos \left(650 \pi t+\frac{\pi}{6}\right)
\left\langle\mathrm{i}^2\right\rangle=50+\frac{100}{2}+0<br/><i2⟩=100<br/>\left. \lt \mathrm{i}^2\right\rangle=100
<i>=10Amp\lt \mathrm{i} \gt =10 \mathrm{Amp}
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