Download File - Ms McRae`s Science

Units of Electricity
1
The electric circuit shown at the right is available to
you.
R1
You are to connect ammeter A so that you can
measure the current intensity, I, flowing through
resistor R1.
R2
Which diagram shows where the ammeter should be placed?
R1
A)
R1
C)
A
A
R2
R2
A
R1
B)
R1
D)
A
R2
2
R2
A student assembled the two circuits illustrated below. Each circuit consists of two identical light bulbs, a 3amp battery and an ammeter.
A1
I=3A
A2
I=3A
What current intensity reading is given by ammeter A1 and by ammeter A2?
A)
A1: 1.5 A and A2 : 1.5 A
C)
A1: 3.0 A and A2 : 1.5 A
B)
A1: 1.5 A and A2 : 3.0 A
D)
A1: 3.0 A and A2 : 3.0 A
3
Four electric circuit diagrams are given below.
Diagram 1
Diagram 3
A
R2
R1 V
R2
V
A
R1
Diagram 2
Diagram 4
R2
A
R1
R1
R2
V
V
Only one of these diagrams correctly represents:
-
a voltmeter connected across the terminals of resistor R1
-
an ammeter measuring the current flowing through resistor R2
Which diagram is it?
4
A)
Diagram 1
C)
Diagram 3
B)
Diagram 2
D)
Diagram 4
Which of the following correctly describes the units of Current and of Potential Difference?
A)
1 A = 1 Cs and 1 V = 1 JC
B)
1 A = 1 C/s and 1 V = 1 J/C
C)
1 A = 1 C/s and 1 V = 1 JC
D)
1 A = 1 Cs and 1 V = 1 J/C
A
5
6
7
8
Which of the following can be used to represent a unit of electric energy?
A)
W
C)

B)
A
D)
J
Which of the following represents a unit of electric energy?
A)
VA
C)
W
B)
J
D)
J/s
What unit is used to express a quantity of electrical charge?
A)
Ampere (A)
B)
Coulomb (C)
C)
Joule (J)
D)
Volt (V)
An electric current is a movement of electric charges.
What is the definition electric current intensity?
9
A)
The work needed to move all charges in a section of the circuit in one second
B)
The work needed to move a charge of +1 coulomb from one end to the other of a section of
a circuit
C)
The quantity of electric charges in a section of a circuit at a given instant
D)
The quantity of electric charge which passes through a section of a circuit in one second
Which statement corresponds to the definition of electric potential?
A)
The quantity of electric charge that flows through an electric circuit in one second
B)
The energy associated with the movement of electrical charges flowing from a source
C)
The energy that flows through an electric circuit in one second
D)
The current intensity that flows through an electric circuit
10
11
12
Which of the following is the definition of current intensity?
A)
The energy carried by an electric charge
B)
The amount of electric charge that flows through a specific point in a circuit per unit of time
C)
The force with which electric charges flow through a conductor
D)
The amount of electric charge flowing through a circuit
Which of the following is the definition of a volt (unit of measurement of potential difference)?
A)
The energy carried by a certain quantity of electric charge
B)
The amount of electric charge that flows through a specific point in a circuit per unit of time
C)
The force with which electric charges flow through a conductor
D)
The amount of electric charge flowing through a circuit
Students in a laboratory conducted the following two experiments on electricity.
Experiment 1:
One student determines that 6 coulombs of charge go through a conductor every 2
seconds.
Experiment 2:
Another student finds that 30 joules of electrical energy are required to move every 3
coulombs of charge.
What units of measurement are associated with the two experimental results determined by the students?
13
A)
Amperes (A) and Joules (J)
B)
Amperes (A) and Volts (V)
C)
Joules (J)and Ohms ()
D)
Volts (V)and Ohms ()
Which of the following statements defines a one-ampere current?
A)
The energy of one joule used to move one coulomb of charge
B)
The energy of one joule that flows through an electric circuit in one second
C)
The rate that energy is used per second
D)
The flow of one coulomb of electrons in one second