Correctly complete the following statements.

1.    The basic unit of electrical current is the _______________.

2.    The _______________ is a device used to indicate the presence of a static electric charge.

3.    A(n) _______________ charged object has an excess of electrons.

4.    The basic unit of voltage is the _______________.

5.    The opposition to the flow of electrons is called _______________.

6.    The basic unit of electrical charge is the  ________________.

7.    The temporary charging of an object without touching is called _______________.

8.    _______________ refers to the force pushing electrons through a wire.

9.   A(n) _______________ does NOT allow electrons to pass through it easily.

10. A(n) _______________ allows electrons to pass through it easily.

11.  A _______________ circuit has only one path for electron flow.

12.  Electricity at rest is called _______________ electricity.

13.  A _______________ circuit has more than one path for electron flow.

14.  A(n) _______________ charged object has a deficiency of electrons.

15.  The equation voltage = current X resistance is a statement of _______________.

16.   _______________  charges tend to repel.

17.  ________________ charges tend to attract.

18. The flow of electrons is called _______________ electricity.

19. The basic unit of electrical resistance is the _______________.

20. The passing of electrons or charge between two
      objects is called _______________.

21.  An object which carries electrons well is called a(n) _______________.

Multiple Choice Section:  Choose the response which best completes each statement or answers each question.

1.    The difference in electrical potential between two places is called
       (1.) current.  (2.) voltage.  (3.) resistance.  (4.) amperage.

2.    According to Ohm's law, if voltage is doubled and resistance stays the same, then
       (1.) current stays the same.  (2.) current is halved.  (3.) current is doubled.
       (4.) current is quadrupled.

3.   According to Ohm's law, if resistance is doubled and current stays the same, then
      (1.)  voltage stays the same.   (2.) voltage is halved.
      (3.)  voltage is doubled.         (4.) voltage is quadrupled.

4.   There is only one path for current to take in a   (1.) series circuit.  (2.) parallel circuit.
       (3.) household circuit.   (4.) 120-volt circuit.

5.   An example of a voltage source is a
      (1.)  bulb.   (2.)  voltmeter.   (3.)  wire.  (4.)  battery.

6.   When current gets too high, a circuit breaker or fuse
       (1.) stops the flow of current in the circuit.
       (2.) enables more current to flow through the circuit.
       (3.) shuts down some appliances on the circuit.
       (4.) decreases the circuit's resistance.

7.   Wet skin increases the risk of electric shock because
       (1.) resistance is higher.  (2.) resistance is lower.
       (3.) voltage is higher.      (4.) current is higher

8.    What is static electricity?
        (1.) any interaction between a person and a metal object
        (2.) the net accumulation of electric charges on an object
        (3.) the charging of a neutral object by an electrically charged object
        (4.) the movement of electrons through a conducting material

9..   Distinguish between a conductor and an insulator.
       (1.) A conductor repels charged objects; an insulator attracts them.
       (2.) A conductor cannot produce static electricity; an insulator can.
       (3.) A conductor allows electrons to move easily through it; an insulator does not.
       (4.) A conductor can be plastic, wood, or glass; an insulator is always metal.

10.  What does an electroscope detect?   (1.) electricity leaking from wall outlets
        (2.) faulty wiring in houses   (3.) electrical problems in automobiles
        (4.) electric charges

11.  Name one thing that is necessary to keep current flowing.   (1.) an unbroken path for electrons to follow
       (2.) a circuit breaker   (3.) static electricity   (4.) a moist chemical paste

12.  What observation about the current in a metal conductor was the basis for Ohm's law?
        (1.) Current depends only on the conductor's resistance.
        (2.) Current depends on resistance and potential difference.
        (3.) Current is unrelated to resistance.
        (4.) The higher the current, the higher the resistance.

13.   Explain why a whole string of holiday lights may not work if one bulb is burned out.
        (1.) The lights are connected in a parallel circuit.
        (2.) The burned-out bulb acts as a semiconductor.
        (3.) The burned-out bulb trips the circuit breaker in your home electrical system.
        (4.) The lights are wired together in a series circuit.

14.   What is the function of a circuit breaker box?
         (1.) to protect against fires caused by overloading circuits
         (2.) to reduce the amount of energy used by household appliances
         (3.) to reduce the voltage of the electricity that comes into your home
         (4.) to prevent lightbulbs from burning out

15.   What determines the amount of energy an appliance uses?
         (1.) its power rating and the number of circuits in your house
         (2.) the number of appliances being used at the same time
         (3.) its power rating and the number of hours per day it is used
         (4.) its size

16.   What do you need to know to calculate the electrical power usage for an appliance?
         (1.) the values of the current and voltage   (2.) the appliance's size and approximate age
         (3.) the number of hours per day the appliance is used
         (4.) the number of appliances using the same circuit
 

17.   When two negative charges are brought close together, they will
         (1.) repel   (2.) attract   (3.) neither attract nor repel   (4.) ground

18.   As the distance from a charged particle increases, the strength of the electric field
        (1.) can't be determined   (2.) remains the same  (3.) increases  (4.) decreases

19.   An example of a good insulator is  (1.) copper   (2.) silver   (3.) wood    (4.) salt water

20.   Connecting a charged object to Earth in order to discharge the object into Earth is called
        (1.) charging   (2.) grounding   (3.) draining   (4.) induction

21.   Resistance in an electrical wire causes electrical energy to be converted to
        (1.) chemical energy   (2.) nuclear energy  (3.) thermal energy   (4.) sound

22.   Which wire would tend to have the least amount of electrical resistance?
         (1.) long    (2.) fiberglass   (3.) hot    (4.) thick
 

Short Answer Section

Please show all appropriate formulas and work for problems 1-4.

1.    Determine the voltage needed to cause a current of 3 amps in a circuit having a resistance of 30 ohms.
 
 
 

2.   Calculate the resistance of a lamp with 3 amperes of current flowing through it in a 24 volt circuit.
 
 
 

3.   What is the current through a wire that has a resistance of 15 ohms, if the voltage is 120 V?
 
 
 
 

4.   What amount of power does an appliance use that operates at a current of 6 A and a voltage
       of 120 V?
 
 
 
 

5.    What kind of circuit is pictured below?          Explain how you know this.	6.  What kind of circuit is pictured below?       Explain how you know this.

7.   List three different factors which increase resistance in an electrical circuit.
 

8.   Explain the difference between the roles of a load versus a switch in an electrical circuit.
 

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