1. Three resistors are connected in series across a 75-V potential difference. R1 is 170-ohm and R2 is 190-ohm. The potential difference across R3 is 21 V.
(a.) Find the current in the circuit.
(b.) Find the resistance of R3.
2. A 25-ohm resistor, a 55-ohm resistor, and a 75-ohm resistor are connected in parallel and placed across a 9.0-V battery.
(a.) What is the equivalent resistance of the parallel circuit?
(b.) What is the current through the entire circuit?
(c.) What is the current through each branch of the circuit?
3. Two resistors, one 130-ohm and the other 210-ohm, are connected in parallel. The resistors are then connected to a battery. If the current through the entire circuit is 0.31 A, what is the voltage of the battery?
4. Resistors R1, R2, and R3 are connected in parallel. R1 is 6-ohm and R2 is 93-ohm. The equivalent resistance of the parallel combination is 26-ohm. What is the resistance of R3?