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1. How much current flows if you connect a 2.34 ohm resistor to a 12.0V battery?

Use I = V/R
I = 12/2.34
I = 5.128A

2. If 0.129 amps of current flow through a 45 ohm resistor, what is the power dissipated?

Use P = (I^2)(R)
P = (.129^2)(45)
P = .7488W

3. If a current of 345mA flows, how much charge will pass by in one minute?

Use I = Q/T
Q = (.345)(60)
Q = 20.7C

4. A 85 ohm heating element is connected to 120V. In what time can the heating element raise the temperature of 2.4kg of water initially at 12C to 85C?

Use (V^2)/R = ((m)(c)(delta Temp))/time
120^2/85 = (2.4*4186*(85-12))/t
t = 4329.02, about 4300sec

5. A 1200W heater runs on alternating current with a peak voltage of 134V. What is its resistance?

Vrms=134/(square root of 2)
R = (94.7^2)/1200
R = 7.48 about 7.5ohms