Question

A certain battery has terminals labeled a and b. The battery voltage is vab = 12 V. a) To increase the chemical energy stored in the battery by 900J, how much charge must move through the battery? b) Should electrons move from a to b or from b to a?

Answer 1

Answer:

(a) The charges of 75 C must flow through battery.

(b) The electrons must flow from a to b.

Explanation:

(a)

The relationship between the energy and voltage is as follows:

Energy = (Voltage)(Current)(Time)

but, (current)(time) = charge

therefore,

Energy = (Voltage)(Charge)

Charge = (Energy)/(Voltage)

Charge = (900 J)/(12 V)

Charge = 75 C

(b)

Since, Vab = Va - Vb = 12 V

Hence, the equation suggest that Va is at higher potential then Vb.

As, the current flows from higher to lower potential.

Thus, electrons must flow from a to b