Q. A rectangular coil of 20 turns and area of cross-section $25\ sqcm$ has resistance of $100\ ohm$. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of $1000\ tesla$ per second, the current in the coil is
A) $1.0\ ampere$
B) $50\ ampere$
C) $0.5\ ampere$
D) $5.0\ ampere$
Explanation
(c) $i = \frac{|e|}{R} = \frac{N}{R} \bullet \frac{\mathrm{\Delta}B}{\mathrm{\Delta}t}A\cos\theta = \frac{20}{100} \times 1000 \times \left( 25 \times 10^{- 4} \right)\cos{0{^\circ}}$
$\Rightarrow i = 0.5\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.