Q172 / 180 · COMEDK 2020 · Physics
A coil of 100 turns carries a current of $5 \mathrm{~mA}$ and creates a magnetic flux of $10^{-5} \mathrm{~Wb}$. The inductance
- A$0.2 \mathrm{mH}$
- B$2.0 \mathrm{mH}$
- C$0.02 \mathrm{mH}$
- Correct answerDNone of these
Solution
Given, number of tums, $N=100$
Current, $I=5 \mathrm{~mA}=5 \times 10^{-3} \mathrm{~A}$
Magnetic flux, $\phi=10^{-5} \mathrm{~Wb}$
Inductance, $L=$ ?
We know that,
$$
\begin{aligned}
N o ̣ &=L I \\
L \quad L &=\frac{N \phi}{I}=\frac{100 \times 10^{-5}}{5 \times 10^{-3}} \\
&=20 \times 10^{-8} \mathrm{H}=02 \mathrm{H}
\end{aligned}
$$
Hence, the correct answer is option: 'D'.