Question

In 10 s, a charge of 25 C leaves a battery, and 200 J of energy are delivered to an outside circuit as a result.

1. What is the p.d. across the battery?
2. What current flows from the battery?

Answer 1

Given: Time (t) = 10 s

Charge (Q) = 25 C

Energy delivered is work done (W) = 200 J

a. Using the relation,

Potential difference = `"Work done"/"Charged moved"`

V = `W/Q`

V = `200/25`

V = 8 V

∴ So the p.d. across the battery is 8 volts.

b. Current = `"Charge"/"Time"`

I = `Q/t`

I = `25/10`

I = 2.5 A

∴ So, a current of 2.5 A flows from the battery.