Question

A flat coil of $500$ turns, each of area $50\, cm ^{2}$, rotates in a uniform magnetic field of $0.14 \,Wb / m ^{2}$ about an axis normal to the field at an angular speed of $150\, rad / s$. The coil has a resistance of $5 \,\Omega$. The induced e.m.f. is applied to an external resistance of $10\, \Omega$. The peak current throuah the resistance is

• A. 1.5 A
• B. 2.5 A
• C. 3.5 A
• D. 4.5 A

Answer 1

Answer: (C)

$N=500, A=50\, cm ^{2}, $
$B=0.14\, Wb / m ^{2}$
$\omega=150 \,rad / s , $
$R=5\, \Omega$
$\varepsilon_{\max }=N B A \,\omega$
$I_{\max}=\frac{\varepsilon_{\max }}{R}=3.5\, A$