A 75W light bulb is attached in series to a battery, ammeter&closed switch.In 40 min 1500 C of charge passes.

Question

What is the voltage of the battery ??

here is my question again with a complete format.

A 75 W light bulb is attached in series to a battery, ammeter and a closed switch. If during a 40 miniute period 1500 C of charge passes through the 75 W light bulb. What is the voltage of the battery.??

thanks

Answer 1

1 coulomb is 1 amp/sec

1500C/2400sec = 0.625 amp

P = I*V

75 = 0.625V

V = 120 volts

Answer 2

amp=amp*sec/sec=1500/2400

=.625 amp

volt=watt/amp=75/.625

=120 volts