Q. The area of hysteresis loop of a material is equivalent to $250\ joule$. When $10\ kg$ material is magnetized by an alternating field of $50\ Hz$ then energy lost in one hour will be (density of material is $7.5\ gm/cm^{3}$)
A) $6 \times 10^{4}J$
B) $6 \times 10^{4}erg$
C) $3 \times 10^{2}J$
D) $3 \times 10^{2}erg$
Explanation
(a) $E = nAVt = nA\frac{m}{d}t = \frac{50 \times 250 \times 10 \times 3600}{7.5 \times 10^{3}} = 6 \times 10^{4}J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.