Download Review for formula, circuit and resistance test

Review for formula, circuit and resistance test
1. Fill in the table giving the symbol and unit(s) for each.
Current
Potential
Voltage
Resistance
Power
intensity
difference
2. Give the formula and then the triangles for each.
Potential difference
Power
Energy 1
3. Give the conversions
W to kW __________
sec to min __________
J to kWh__________
min to sec________
Energy
Time
Energy 2
sec to hrs___________
hrs to sec___________
J to kJ _______
4. How much power did an electric lawn mower use if it used 45 000 J of energy in the 50 minutes it
took to mow the lawn?
5. How much time was a fish tank on when it needed 0.5 A, 100 V and 45 000 J of energy?
6. A man used the computer for 7 hours and used 500 W of power. How much energy did it take to
use the computer for seven hours?
7. What is the potential difference of a light bulb when it uses a 200 Ω resistor and 0.4 A?
8. A radio is on for 150 minutes and has 450 W of power. What is the energy in kWh?
9. A toaster takes 300 seconds to toast a piece of bread. If it uses 400 W of power how much
energy will be used in J?
10. If a TV used 7 000 J of work and 90 W of power. How many hours did you watch TV for?
11. An electric radiator with a resistance of 40  is connected to a 220 V circuit for 1.00 hour. What
is the power of this radiator?
A) 1.21 kW
B) 5.50 kW
C) 19.8 kW
D) 1 210 kW
12. On an electric heater are written the following specifications : 110 V - 550 W. What is the
resistance of this heater?
A) 61 
B) 22 
C) 5 
D) 0.20 
13. While having breakfast, you notice the following information on the
specification plate of the toaster:
You also note that this toaster toasts the bread in 1.5 minutes.
120 V
6A
60 Hz
What quantity of electrical energy is consumed by the toaster's element to toast the bread?
A) 720 J
B) 1 080 J
C) 10 800 J
D) 64 800 J
14. Calculate the resistance value in the circuit below.
15. During a lab experiment, you have to assemble a circuit based on the following information:
The circuit is composed of a 6.0-V battery connected to a 10-Ω resistor. It includes an ammeter
and a voltmeter connected to the resistor terminals.
a)
Draw the circuit diagram, including the measuring instruments.
b)
What values will the ammeter and voltmeter display?
c)
How much energy will the resistor release in one minute’s work?
16. Draw a series and parallel circuit, each with two resistors. Include a switch and a fuse for the
controlling the whole circuit.
Series
Parallel
17. Draw a circuit where current intensity has 4 possible pathways. Use the specifics below when
drawing the circuit
- Place a voltmeter that measures the potential difference coming from the power source, use Vt
as your symbol.
- Place a voltmeter that measures the potential difference across resistor R2, use V2 as your
symbol.
- Place an ammeter that measures the current intensity from the power source, use At as your
symbol.
- Place an ammeter that measures the current intensity through resistor R3, use A3 as your symbol.
- Place an ammeter that measures the current intensity through resistor R3 and resistor R4, use A4
as your symbol.
- Place a switch that will cause the whole circuit to stop working when it is open.
- Place a switch that will cause resistor R1 to stop working when it is opened.
- Place a switch that will cause resistors R2, R3, and R4 to stop working when it is opened.
- Place a fuse to control the whole circuit
- Place a switch to control resistor 3
a)
b)
18. Look at the electrical circuit.
Determine if each circuit is an open or closed one.
Determine if the light bulb will be on for each circuit.
Circuit A
Circuit B
19. In the lab, you have been given the following materials: a battery, three lamps, two switches and a
fuse. You must assemble a circuit containing the battery, one switch and the three lamps. The
lamps are to be connected in parallel, and they must all turn on at the same time and give off the
same intensity of light. The fuse must be installed so that the total current intensity does not
exceed 2.4 A.
a) Draw the diagram for this electrical circuit.
b) What would happen if the current in the circuit in question a) were to exceed 2.4 A?
20. Fuses and breakers perform the same function in electrical circuits. What is this function called?
21. When a lamp is switched off, is the electrical circuit to the light bulb open or closed? Explain your
answer.
22. When you go to a friend’s house and ring the doorbell, an electrical circuit is activated, and the
doorbell rings.
a)
When you press the button for the doorbell, you close an electrical circuit. Which
function does the push button perform in the circuit?
b)
The doorbell is covered in plastic. Why? Which function does this small round plastic
cover perform?
23. Four electric circuit diagrams are given below.
You wish to measure the potential difference across the terminals of resistor R2.
Which diagrams show a correctly connected voltmeter?
A) 1 and 3
B) 2 and 4
C) 1 and 2
D) 2 and 3
24. The following electric circuit consists of a power supply, VT, connected to three resistors (R1, R2
andR3). Which of the following circuit diagrams shows the correct connection for an ammeter A
that measures the current flowing through resistor R1?
25. An electrical circuit consists of a power source, two switches (S1 and S2) and two light bulbs (L1
and L2). The following table shows what happens to both light bulbs:
Switch
Light Bulb
S1
S2
L1
L2
open
open
out
out
closed
open
bright
out
Which of the following circuit diagrams illustrates the results shown in the table above?
A)
C)
B)
D)
26. The following table gives the characteristics of four electrical conductors.
Conductor
Length
Diameter
Temperature
F1
1m
2 mm
-20°C
F2
3m
2 mm
50°C
F3
1m
1 mm
50°C
F4
3m
1 mm
-20°C
Which is the best electrical conductor?
A) F1
B) F2
C) F3
D) F4
27. A circuit consists of a power supply, a light bulb and two terminals that can be connected to a
rod. The copper rods illustrated below are inserted into the circuit one at a time. The rods are
the same temperature, but they have different dimensions.
Which rod will offer the least resistance to the flow of electric current?
A) rod 1
B) rod 2
C) rod 3
28. Use the results to answer the questions.
Voltage (V)
0
1.5
3.0
Current (A)
0
0.35
0.70
Draw a resistance graph
4.5
1.0
6
1.4
D) rod 4
7.5
1.7
Find the resistance
9
2.0
29. The following graph describes the behavior of three resistors subjected to different voltages.
Which is the resistor would you use as the best conductor?
Justify your answer using calculations.
V
(V)
1
4.0
3.5
2
3.0
2.5
3
2.0
1.5
1.0
0.5
0
0.1
0.2
03
0.4
0.5
0.6
0.7
0.8
IV