Q. If $t_{1}\ and\ \ t_{2}$ are the times taken by two different coils for producing same heat with same supply, then the time taken by them to produce the same heat when connected in parallel will be
A) $t_{1} + t_{2}$
B) $\frac{t_{1}t_{2}}{t_{1} + t_{2}}$
C) $\frac{2t_{1}t_{2}}{t_{1} + t_{2}}$
D) $t_{1}t_{2}$
Explanation
(b) In parallel $\frac{1}{t_{p}} = \frac{1}{t_{1}} + \frac{1}{t_{2}}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ t_{p} = \frac{t_{1}t_{2}}{t_{1} + \ t_{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.