Battery capacity is measured in Amp-hours. It describes how longa battery can maintain a current of so many Amps, whilstmaintaining a constant voltage. For example 4 amp-hour battery canoutput a current of 1 amp for 4 hours, or 2 amps for 2 hours, or 4amps for 1 hour etc etc before the voltage begins to drop and thebattery runs flat.

1.What is the power output of the battery while the bulb is atconstant brightness in circuit D?

2. What is the total energy output of the battery in circuit D,if you start with a fresh battery and let the circuit run until thevoltage begins to drop? The battery has a capacity of 3amp-hours.

3. In which circuit will the bulb stay at a constant brightnessfor longest?

 

M + + + A C D