Q. The amount of charge $Q$ passed in time $t$ through a cross-section of a wire is $Q = 5t^{2} + 3t + 1.$The value of current at time $t = 5\ s$ is
A) 9A
B) 49A
C) 53A
D) None of these
Explanation
(c) $i = \frac{dQ}{dt} = \frac{d}{dt}\left( 5t^{2} + 3t + 1 \right) = 10t + 3$
When $t = 5s,\ i = 10 \times 5 + 3 = 53\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.