Chapter 7:
Electricity
Practice Test
1.
How much energy is used when a 110 kW appliance is used for 3 hours?
a.
300 kWh
b.
36.7 kWh
c.
0.027 kWh
d.
330 kWh
Hint
2.
If a voltage difference of 3 V causes a 1.5 A current to flow in a circuit, what is the resistance in the circuit?
a.
0.5 Ω
b.
2 Ω
c.
1.5 Ω
d.
4.5 Ω
Hint
3.
What is the voltage difference in a circuit that uses 2420 W of power if 11 A of current flows into the circuit?
a.
0.0045 V
b.
2431 V
c.
532,400 V
d.
220 V
Hint
4.
A circuit has a resistance of 4 Ω. What voltage difference will cause a current of 1.4 A to flow in the circuit?
a.
5.4 V
b.
0.35 V
c.
5.6 V
d.
2.86 V
Hint
5.
The current in an appliance is 3 A and the voltage difference is 120 V. How much power is being supplied to the appliance?
a.
360 W
b.
0.025 W
c.
40 W
d.
123 W
Hint
6.
An electric clothes dryer uses 4 kW of electric power. How long did it take to dry a load of clothes if electric power costs $0.09/kWh, and the cost of using the dryer was $0.27?
a.
0.75 h
b.
0.3 h
c.
3 h
d.
0.5 h
Hint
7.
What is the current flowing into a microwave oven that requires 700 W of power if the voltage difference is 120 V?
a.
5.8 A
b.
84,000 A
c.
820 A
d.
0.17 A
Hint
8.
How many amperes of current will flow in a circuit if the voltage difference is 9 V and the resistance in the circuit is 3 Ω?
a.
12 A
b.
27 A
c.
3 A
d.
0.33 A
Hint
9.
How much does it cost to light 6 100 W lightbulbs for 6 hours if the price of electrical energy is $0.09/kWh?
a.
$3.24
b.
$4.00
c.
$324
d.
$0.32
Hint
10.
A television has a power rating of 210 W. If the television uses 1.68 kWh of energy, for how long has the television been on?
a.
1.25 h
b.
8 h
c.
352.8 h
d.
125 h
Hint
