A current carrying solenoid of cross-sectional area $2\, cm^2$ and 2000 turns has a magnetic moment of $0.80\, Am^2$. The current flowing through the solenoid is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 2 A
$\text{Given: Cross-sectional area } A = 2~\text{cm}^2 = 2 \times 10^{-4}~\text{m}^2$
$\text{Number of turns } N = 2000$
$\text{Magnetic moment } M = 0.80~\text{A·m}^2$
$\text{Magnetic moment of solenoid: } M = N I A$
$I = \frac{M}{N A} = \frac{0.80}{2000 \cdot 2 \times 10^{-4}}$
$I = \frac{0.80}{0.4} = 2~\text{A}$
$\text{Answer: } I = 2~\text{A}$