A rechargeable battery has , internal resistance and battery capacity (total charge) .
When the battery is fully charged, a light bulb is connected to it for 8 hours (see picture above). The light bulb has specs and . We assume the light bulb has constant resistance (independent of the current) and the emf of the battery remains constant.
After these 8 hours the battery is disconnected from the light bulb and connected in this circuit for charging:
The charger consists of a ideal voltage source with (with no internal resistance) and a resistor in series.
(a) What is the minimum time that is needed to fully recharge the battery (with )
(b) What should the resistance be to fully recharge the battery in exactly 1 hour?
Comments