Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
An inductance coil has a resistance of $100 \Omega$. When are a.c. signal of frequency $100 \mathrm{Hzis}$ applied to the coil, the voltage leads the current by $45^{\circ}$. The inductance of the coil in henry is $\left[\sin 45^{\circ}=\cos 45^{\circ}=\frac{1}{\sqrt{2}}\right]$
PhysicsAlternating CurrentMHT CETMHT CET 2022 (06 Aug Shift 2)
Options:
  • A $\frac{1}{\pi}$
  • B $\frac{5}{2 \pi}$
  • C $\frac{2}{\pi}$
  • D $\frac{1}{2 \pi}$
Solution:
1856 Upvotes Verified Answer
The correct answer is: $\frac{1}{2 \pi}$
The phase angle in an LR circuit is given by, since $\phi=45^{\circ}$,
$\tan \phi=\frac{X_L}{X_R}=1$
Resistance of inductive coil $X_L=X_R=100 \Omega$
Thus, inductance of coil $L=\frac{X_L}{2 \pi f}$
$\therefore L=\frac{100}{2 \pi \times 100 \mathrm{~s}^{-1}}=\frac{1}{2 \pi} \mathrm{H}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.