State the 3 different equations you can use to solve for Power in an electric circuit.
What is P = IV, P = I^2R, P = V^2/R
100
One kilowatt-hour (kWh) is a measure of what?
What is Energy.
100
If the voltage across a circuit is kept constant and the resistance is doubled, what effect does this have on the circuit's current?
If the resistance is doubled, the current is halved.
200
Any closed loop or conducting path allowing electric charges to flow is called a __________?
What is an electric circuit.
200
Please state one of the forms of Ohm's Law.
What is R = V/I
200
Please state the 3 equations you can use to solve for thermal energy given off in a resistor.
What is E = Pt, E = I^2Rt, P = (V^2/R)t
200
1 (kWh) is equal to ________ Watts times ________ seconds.
What is 1000 Watts times 3600 seconds.
200
What is the effect on the current in a circuit if both the voltage and the resistance are doubled?
No effect. V = IR so I = V/R, and if the voltage and the resistance are both doubled, the current will not change.
300
Fill in the blank. Power is a measure of ______ per ________.
What is energy per time.
300
A 30-V battery is connected to a 10-Ohm resistor. What is the current through the circuit?
What is 3.00-A
300
A heater has a resistance of 10.0-Ohms. It operates on 120-V. What is the thermal energy supplied by the heater in 10.0 seconds?
What is 14.4 kJ or 14,400 Joules
300
The current through a toaster that is connected to a 120-V power source is 8.0-A. How much energy is being used in 2 minutes?
What is 115.2 kJ or 115, 200 Joules
300
How much energy is delivered to a 60.0-W lightbulb if the bulb is left on for 2.5 hours?
What is 5.4x10^5 J
400
A car battery causes a current of 2.0-A through a lamp and produces 12-V across it. What is the power used by the lamp?
What is 24-W
400
A 75-W lamp is connected to a 125-V source. What is the resistance of the lamp?
What is 210-Ohms
400
The resistance of an electric stove element at operating temperature is 11-Ohms. If you place 220-Volts across it, what is the thermal energy given off in 30.0-s?
What is 1.3x10^5 Joules
400
A digital clock has a resistance of 5,000-Ohms and is plugged into a 120-V outlet. How many kilowatt-hours are used if the clock is ran continuously for 10 days.
What is .69 kWh
400
A heating coil has a resistance of 4.0-Ohms and operates on 120 Volts. What energy is supplied to the coil in 5 minutes?
What is 1.1x10^6 J
500
A 6.0-V battery delivers a 0.50-A current to an electric motor for 5 minutes. How much electric energy is delivered?
What is 900 J
500
A lamp draws a current of 0.50-A when it is connected to a 120-V source. What is the power consumption of the lamp?
What is 60 Watts
500
A 50-W lightbulb is 34% efficient. That means 34% of the electric energy is converted to light energy. How many joules of of energy are converted into light each minute? How many joules are converted into thermal energy?
What is 1020 Joules converted to light and 1980 Joules converted to heat.
500
If I have $1.50, and electricity costs $0.15 per kWh, how long could I play my 100-W stereo for?
What is 100 Hours.
500
A heating coil has a resistance of 4.0-Ohms and operates on 120 Volts. At $0.08 per kWh, how much does it cost to operate the heating coil for 30 minutes per day for 30 days?