Question

A coil of resistance $10\Omega$ and $1000$ turns have the magnetic flux line of $5.5\times {10}^{-4}Wb$. If the magnetic flux changed to $5\times {10}^{-4}Wb.$ in $0.1sec$, then the induced charge in coil is

• A. $50\mu C$
• B. $5\mu C$
• C. $2\mu C$
• D. $20\mu C$

Answer 1

The correct option is B $5\mu C$

Given,

Resistance, $R=10\Omega$

Number of turns, $N=1000$

Change in flux, $\Delta \varphi =5.5\times {10}^{-4}-5\times {10}^{-4}=0.5\times {10}^{-4}Wb$

Charge, $Q=I\Delta t=\frac{\Delta \varphi }{R}$

$Q=\frac{0.5\times {10}^{-4}}{10}=5\times {10}^{-6}$

Hence, charge is $5\mu C$