physics
posted by edd on .
Derive the expressions for the equivalent resistence of two resistors R1 and R2 for the cases
when they are (a) in series and (b) in parallel. Hint: Set up the circuit with a constant Voltage
source V (it is not necessary to put in an exact value for V ). Define the current which leaves
(and returns to) the voltage source as I, and for the parallel circuit define the currents in each
leg of the circuit as I1 and I2. Write down Ohms law for each resistor, and also apply Kirchovâ€™s
loop rule and juntion rule for each circuit. Manipulate and combine all these equations to obtain
an expression V = ReqI where Req is some function of R1 and R2 that you have determined. Req
is the equivalent resistance for the circuit.

This assignment is identical to the one millions before you have suffered thru. Follow the directions, and you will find a way through it.
Do you have any questions on it? It is rather straightforward as written.