Name: 
 

Ch 22 Currrent Electricity - Open Book



True/False (Value 5)
Indicate whether the statement is true or false.
 

 1. 

The cables used to transfer electric energy from the generating station to the consumers must be of low resistance to reduce losses due to joule heating.
 

 2. 

Electric energy is transferred from generating stations to consumers’ premises at extremely low voltage.
 

 3. 

A resistor is a device that controls current in electric circuits.
 

 4. 

A resistor is a device that converts chemical energy into electric energy.
 

 5. 

An ampere is a unit used by electric companies to measure electrical energy use.
 

Multiple Choice (Value 10)
Identify the choice that best completes the statement or answers the question.
 

 6. 

Which of the following circuits can be used to test whether or not a wire of a laminated heating element is cut internally?
a.
mc006-1.jpg
c.
mc006-3.jpg
b.
mc006-2.jpg
d.
mc006-4.jpg
 

 7. 

A/An _____ is described as the flow of positive charges that move from a higher to lower potential energy.
a.
electron flow
c.
electric circuit
b.
conventional current
d.
conventional circuit
 

 8. 

_____ is described as a property that determines how much current will flow for a given battery voltage.
a.
Resistance
c.
Kilowatt-hour
b.
Resistor
d.
Thermal energy
 

 9. 

_____ is a property that determines how much current will flow for a given source voltage, whereas a _____ is a device that controls the current in a circuit.
a.
Resistance, resistor
c.
Resistor, resistance
b.
Resistance, battery
d.
Battery, resistance
 

 10. 

A sensor uses 2.0 mc010-1.jpg 10-4 A of current when it is operated by a 3.0 V battery.  What is the resistance of the sensor circuit?
a.
6.7 mc010-3.jpg 10-5 ohms
c.
1.5 mc010-5.jpg 104 ohms
b.
6.0 mc010-4.jpg 10-4 ohms
d.
6.9 mc010-6.jpg 104 ohms
 

 11. 

A/An _____ is described as a closed loop or pathway that allows electric charges to flow.
a.
electric circuit
c.
parallel connection
b.
conventional current
d.
series connection
 

 12. 

A lamp uses 15 W of power when it is connected across 25 V.  What is the current through the lamp?
a.
0.60 A
c.
9.38 mc012-1.jpg 103 A
b.
1.67 A
d.
93.8 mc012-2.jpg 103 A
 

 13. 

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?
a.
0.167 W
c.
24 W
b.
6 W
d.
48 W
 

 14. 

The current through a lightbulb connected across the terminals of a 125 V outlet is 0.50 A.  Assuming 100% efficiency, at what rate does the bulb convert electric energy to light?
a.
0.004 W
c.
63 W
b.
25 W
d.
250 W
 

 15. 

A/An _____ is described as the flow of electric charge or current equal to one coulomb per second.
a.
volt
c.
capacitance
b.
capacitor
d.
ampere
 

Matching (Value 4)
 
 
Define the following terms by matching them with the correct definition.
a.
electric current
e.
resistance
b.
conventional current
f.
resistor
c.
battery
g.
ampere
d.
electric circuit
h.
kilowatt-hour
 

 16. 

a flow of charged particles
 

 17. 

an energy unit used by electric companies to measure energy use
 

 18. 

a device with specific resistance; used to control current in circuits
 

 19. 

a device that converts chemical energy to electric energy
 

Problem (Value 24)
 

 20. 

There is a 0.40-A current in resistor X when it is connected to a 2.0-V battery. A 0.25-A current is in a second resistor, Y, when it is connected to a 4-V battery. There is a 0.50-A current in a third resistor, Z, when it is connected to a 5.0-V battery. Find the resistor that has the maximum resistance and the resistor that has the least resistance.
 

 21. 

How much energy is consumed in 10 minutes by a bulb with a resistance of 50 W when connected to a 50-V battery?
 

 22. 

The table below shows a list of some electric appliances with the values of their potential differences and current. Which appliance consumes the most power?
AppliancePotential difference (V)Current (A)
Television240.75
Drill1101.6
Bulb124.0
Amplifier1100.2
 

 23. 

Bulb P is rated 60 W, 110 V and bulb Q is rated 100 W, 110 V. Which of the bulbs has the higher resistance?
 

 24. 

An electric iron dissipates 1.5 kW when connected to a 110-V supply. By what factor should the resistance of its heating element be changed so that it consumes only 1 kW?
 

 25. 

A hair dryer rated at 1.5 kW, 110 V is used for 4 minutes every day for one month. Calculate the energy delivered to the hair dryer in one month in kilowatt-hours.
 

 26. 

How many kilowatt-hours of energy does an appliance rated as pr026-1.jpg W and 1.10 pr026-2.jpg 102 V consume in 15.0 minutes?
 

 27. 

The table below shows a list of some electric appliances with their power ratings and the duration for which they are used in Jody’s house over one month. Which appliance consumed the maximum total energy and how many kilowatt-hours were consumed?
AppliancePower rating (W)Duration of use (hours)
Television10060
Drill10001
Bulb60150
Amplifier12060
 



 
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