A source of e.m.f. `E = 15V` and having negligible internal resistance is connected to a variable resistance so that the current in the circuit increases with time as `i = 1.2 t +3` Then, the total charge that will flow in first five second will be

Options

A. 10 C
B. 20 C
C. 30 C
D. 40 C

Answer

C

Explanation

`E = 15 V, i = 1.2t + 3`
`q = int_(0)^(5)idt =int_(0)^(5) (1.2 t + 3) dt`
`(1.2 xx 25)/2 + 15 = 30 C`