A motor with an internal resistance of R(motor) = 50 Ohmsrequires a potential difference of V(motor)=20V to work properly.As you don't have a 20V power source, you place two 12V batteriesin series with a custom-built resistor with resistance R1.
(a) How much current moves through the motor when it is workingproperly?
(b) What must be the resistance of your custom-built resistor sothat the potential difference across the motor is 20V?
(c) If you built your resistor from aluminium wire with diameter of0.03mm and a resisticity of 2.65*10^-8 Ohmes meter, what length ofwire must you use to create the necessary resistance of R1?
(d) What is the ratio of the power used by the motor to the powerdissipated by the resistor, P(motor)/P(R1)?
