Question

cm2If a coil of $40$ turns and area $4.0c{m}^2$ is suddenly removed from a magnetic field, it is observed that a charge of $2.0\times {10}^{-4}C$ flows into the coil. If the resistance of the coil is $80\Omega$, the magnetic flux density in Wb/m2 is

• A. $0.5$
• B. $1.0$
• C. $1.5$
• D. $2.0$

Answer 1

Answer: (B)

$1.0$

$\Delta Q=\frac{\Delta \Phi }{R}$

$=\frac{n\times BA}{R}$

$\rho B=\frac{\Delta Q\times R}{nA}$

$=\frac{2\times {10}^{-4}\times 80}{40\times 4\times {10}^{-4}}$

$=1wb/m^2$