Question

The current flowing through a wire depends on time as $I=3t^{2}+2t +5.$ The charge flowing through the cross section of the wire in time from $t = 0$ to $t = 2$ sec. is

• A. 22 C
• B. 20 C
• C. 18 C
• D. 5 C

Answer 1

Answer: (A)

22 C

Answer 2

Charge $Q =\int\limits_{0}^{2}\left(3 t^{2}+2 t+5\right) d t$
$=\left[t^{3}+t^{2}+5 t\right]_{0}^{2}$
$=8+4+10=22\, C$