1. A charging RC circuit controls the intermittent windshield wipers in a car. The emf is 12.0 V. The wipers are triggered when the voltage across the 110 µF capacitor reaches 10.0 V; then the capacitor is quickly discharged (through a much smaller resistor) and the cycle repeats. What resistance should be used in the charging circuit if the wipers are to operate once every 1.60 s?

  kΩ

2. A length of wire has a resistance of 600 Ω. The wire is cut into N identical pieces which are then connected in parallel. The resistance of the parallel arrangement is 24 Ω. Find N.

  

3. A single household circuit operates at 120 V and is protected by a 15 A circuit breaker. How many 60 W lamps can be operated simultaneously without tripping the circuit breaker?

  

4. In the figure below, what is the net resistance of the circuit connected to the battery? Each resistance in the circuit is equal to 4.8 kΩ.

  kΩ

5. Determine the power dissipated in the R2 resistor in the circuit shown in the drawing. (R1 = 4.0 Ω, R2 = 7.0 Ω and V1 = 16 V.)

  W

6. Find the current in the 5.0 Ω resistor in the drawing (V1 = 21.0 V and R1 = 27.0 Ω).

  A

7. Determine the equivalent capacitance between A and B for the group of capacitors in the drawing. Let C1 = 12 µF and C2 = 4.0 µF.

  µF

8. For the circuit shown in the drawing, find the voltage (V) of the battery if R1 = 2.10 Ω and R2 = 7.50 Ω

  Volts

9. One heater uses 370 W of power when connected by itself to a battery. Another heater uses 266 W of power when connected by itself to the same battery. How much total power do the heaters use when they are both connected in series across the battery?

  W

10. For the circuit shown in the drawing, find the current in the R resistor. Let V = 28.0 Volts, R = 18.0 Ω.

  Amp