Question

A flashlight draws 0.133 A from a 3.0-V battery pack in 2.0 minutes (a) how much charge flows from the battery (b) how much energy does the battery supply, (c) how many electrons have passed any point in the circuit every second? ___________ x 10 ____________ electrons

Answer 1

Answer:

(a) 15.96 C (B)47.88 J (C) $9.975\times 10^{19}electron$

Explanation:

We have given current i =0.133 A

Voltage of the battery V =3 volt

Time t=2 minute=2×60=120 sec

(a) We have to find the charge

charge Q = current ×time

So $Q=0.133\times 120=15.96C$

(B) The energy supplied by the battery

Energy = charge ×potential difference

So $E=15.96\times 3=47.88J$

(C) We know that charge on one electron $e=1.6\times 10^{-19}C$

So number of electron $n=\frac{Q}{e}=\frac{15.96}{1.6\times 10^{-19}}=9.975\times 10^{19}electron$