Q. Two filaments of same length are connected first in series and then in parallel. For the same amount of main current flowing the ratio of the heat produced is
A) 2 : 1
B) 1 : 2
C) 4 : 1
D) 1 : 4
Explanation
(c) $R_{s} = R + R = 2R\ and\ {\ \ R}_{P} = \frac{R \times R}{R + R} = R/2$
$\frac{H_{1}}{H_{2}} = \frac{I^{2}R_{S}}{I^{2}R_{P}} = \frac{R_{S}}{R_{P}} = \frac{2R}{R/2} = \frac{4}{1}$.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.