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Test your basic knowledge |
Basic Electricity
Start Test
Study First
Subject
:
engineering
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. What is the unit of measurement of electrical current?
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
Amperes
Common - not rechargable - gradually discharges when in storage(All of the above)
5%
2. A resistor is color coded brown - green - orange. What is its resistance?
15 -000 ohms - 20%
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Heat
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
3. Which type of cell can be recharged?
Bare - covered - insulated - stranded - cable(All of the above)
50 Ohms
1/1000th of an inch
Secondary cell
4. What makes electrons flow?
Potential difference
Relationship between current and potential difference
Opposition to electrical current
Wire splices
5. What is the relationship between cells and batteries?
Breakdown voltage
The rate of doing work
Cells can be connected together to make a battery
Cables
6. What is the difference between AC and DC?
DC flows continuously in one direction and AC potential difference and current both change direction
The rate of doing work
75 Ohms
Chemical action
7. What is the measure of potential difference?
Mutual induction
Common - not rechargable - gradually discharges when in storage(All of the above)
Volts
Area and spacing of capacitor - static current in the capacitor(both A and B)
8. What is the purpose of a raceway?
Potential difference
15 -000 ohms - 20%
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Porcelain
9. What is produced when an alternator rotates 360 electrical degrees through a magnetic field?
Voltage
Resistance value can not be changed
Alternating current
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
10. What is an arrangement of materials that create a potential difference by chemistry?
Cell
Heat
By their covering
Alternating current
11. What is a common form used in conductors?
Cables
A magnetic field
First digit
1/1000th of an inch
12. What is the use of the electromagnet?
High resistance
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Plastic - Rubber - Friction(all of the above)
13. What cannot be transformed to higher or lower potential differences?
Heat
DC current
Battery
Grounding wire
14. When reading resistance color codes - what does the fourth band indicate?
Tolerence
Strength of the charge
The direction the negative charge moves
Potential difference
15. What is a characteristic of insulators?
Electromagnetism
Silver
Bare - covered - insulated - stranded - cable(All of the above)
High dielectric and mechanical strength - tempurature and moisture resistance - flexible(All of the above)
16. What is a rigid metal conduit?
15 -000 ohms - 20%
Breakdown voltage
50 Ohms
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
17. What determines whether a spark can be produced?
Heat and current control(both a and c)
Strength of the charge
Plastic - Rubber - Friction(all of the above)
Volts
18. What is resistance in electrical terms?
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Stores electrical charge
Porcelain
Opposition to electrical current
19. What does resistance produce?
The rate of doing work
Heat and current control(both a and c)
DC current
Heat
20. What does a transformer transform?
Fixed - tapped - variable(all of the above)
Potential difference - E*I - current times current change from point to point(all of the above)
The relationship of potential difference to current
Silver
21. How do you read resistor color codes?
From the negative battery terminal to the positive terminal
1 watt
Start with the band on the end and read to the center
Parallel
22. When does a DC circuit oppose current flow?
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Opposes any change in the current flowing in a circuit
Common - not rechargable - gradually discharges when in storage(All of the above)
Does not move
23. What is true about a dry cell?
Volts
1/1000th of an inch
Opposes any change in the current flowing in a circuit
Common - not rechargable - gradually discharges when in storage(All of the above)
24. What is the unit of measurement of resistance?
Potential difference
Insulation resistance
Ohms
10
25. What is the unit of measurement of potential difference?
--^V^V^V^---
Start with the band on the end and read to the center
10%
Volts
26. If the fourth color band is gold - this means the measured value of the resistance is what percent of the marked value?
A magnetic field
5%
Volts
Resistance increases as the conductor length increases
27. What does an object have if a magnetic field acts on it?
Energy
Unlike poles attract
Magnetic properties
Common - not rechargable - gradually discharges when in storage(All of the above)
28. What is a type of mechanical transducer?
Solenoid and Relay(both A and B)
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Porcelain
Heat
29. How is the heat production measured in a resistor?
Insulation resistance
Strength of the charge
1 watt
Potential difference - E*I - current times current change from point to point(all of the above)
30. What makes electrons flow?
Grounding wire
Bonding and grounding
Strength of the charge
Potential difference
31. What is the fundamental property of insulators?
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Battery
Insulation resistance and Dielectric strength(Both A and B)
Moving vehicles
32. Which way is the current going in the circuit shown?(electron flow)
Alternating current
Resistance value can not be changed
Purging
From the negative battery terminal to the positive terminal
33. The generator is what method of creating potential energy?
Electromagnetism
Composition of the resistor
--^V^V^V^---
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
34. What type of circuit has two or more paths for current to follow?
Parallel circuit
High dielectric and mechanical strength - tempurature and moisture resistance - flexible(All of the above)
Mutual induction
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
35. Identify the general blueprint symbol for inductors.
Solenoid and Relay(both A and B)
Ability to store an electric charge
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Symbol
36. What are the two generic methods to eliminate static electricity from metal objects?
Bonding and grounding
Opposition to electrical current
5%
Moving vehicles
37. What is a type of capacitor?
Fixed - Electrolytic - Variable(all of the above)
Tolerence
Magnetic properties
From the negative battery terminal to the positive terminal
38. What is 'difference in potential(potential difference) - per unit of charge - between two points'?
Voltage
5%
Ohms
Battery
39. What is the purpose of resistors in electrical circuits?
Produce heat - light - or limit current to control it(all of the above)
Alternating current
Voltage
First digit is 9
40. What is the basic law of magnetic force?
American wire gauge(AWG)
Unlike poles attract
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Current flows in one direction - potential differences across a load does not change(Both A and B)
41. When reading resistance color codes - what does the first band indicate?
Electromagnetic field
Heat and current control(both a and c)
A magnetic field
First digit
42. What is the relationship between magnetism and electricity?
Magnetism produces a field and the field exerts force on a moving charge - every moving electrical charge produces a magnetic field - and the magnetic field is strong when the electrical charge is strong and moves rapidly(all of the above are true)
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
Two
Insulation resistance and Dielectric strength(Both A and B)
43. What does a moving charge produce?
A magnetic field
Electromagnetic field
Volts
Cell
44. What is the purpose of capacitors in electrical circuits?
It increases or decreases the potential difference of AC electricity - It is effective with almost no loss of power - It's use- cost is very low(All of the above)
Stores electrical charge
The direction the negative charge moves
Common - not rechargable - gradually discharges when in storage(All of the above)
45. What is needed for electric heating elements and the filaments of light bulbs?
Volts
Ability to store an electric charge
Insulation resistance
High resistance
46. What is the name for electrical resistance of insulation?
Common - not rechargable - gradually discharges when in storage(All of the above)
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Insulation resistance
Relay
47. What is a DC circuit characteristic?
Potential difference
Opposes any change in the current flowing in a circuit
Current flows in one direction - potential differences across a load does not change(Both A and B)
Use an effect to produce another effect
48. What is power?
12 volts
Plastic - Rubber - Friction(all of the above)
The rate of doing work
Parallel circuit
49. Which of the following is a type of resistor?
--^V^V^V^---
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Two
Fixed - tapped - variable(all of the above)
50. How do static charges distribute themselves?
Evenly over the surface of a sphere and concentrated on points of objects(both A and C)
Insulation resistance and Dielectric strength(Both A and B)
Ohms
Common - not rechargable - gradually discharges when in storage(All of the above)