Unit 11: Circuits

Roller Coaster Model of Circuits

Kirchoff's Laws

Homework for internal resistance and RC circuits.

1. A battery has an EMF of 12 V and an internal resistance of 1 Ohm. If the battery is hooked up to 5 Ohm light bulb, what will be the current and the voltage across the battery?

2. A battery has an EMF of 12 V and an unknown internal resistance. The battery is then hooked up to a light bulb of unknown resistance. The voltage across the battery is then measured to be 10 V and the current is measured as 2 Amps. Determine the internal resistance of the battery and the unknown resistance.

3. A battery has an unknown EMF and an internal resistance of 1 Ohm. The battery is hooked up in series to two resistors. One of the resistors is 2 Ohms, the other is unknown. If the voltage measured across the battery is 10 V and the current is 2 A, determine the EMF and the unknown resistor.

4. A 100 kiloOhm resistor is connected to a 100 microF Capacitor and a 12 V battery determine q, i, v(cap), and v(res) at t = 0 and t = much later.

sketch graphs of the above FOUR quantities vs. time.

5. After the a long time the battery in the above circuit is disconnected and the capacitor is connected to the resistor and allowed to discharge. Determine

q, i, v(cap), and v(res) at t = 0 and t = much later.

sketch graphs of the above FOUR quantities vs. time.

Review Sheets