Question

A hydrogen fuel cell supplies power for a small motor. the fuel cell delivers a current of 0.5 a and a voltage of 0.43 v. what is the power supplied to the motor by the fuel cell?

Answer 1

The power supplied to the motor by the fuel cell is 0.31 watts.

The current , I is 0.5 A.
Voltage, V is 0.43 V

From ohm's law: V = IR 
Thus, R = 0.43/0.5 = 0.86Ω

Now, Power = $I^{2}$R
                     = 0.5 ×0.5×0.86
                     = 0.215 W