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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 produced when an alternator rotates 360 electrical degrees through a magnetic field?
Chemical action
Alternating current
Start with the band on the end and read to the center
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
2. What is an electromagnet?
Common - not rechargable - gradually discharges when in storage(All of the above)
Resistance value can not be changed
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
By their covering
3. What is dielectric strength?
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Parallel circuit
How much potential difference can a material withstand before breaking down
20%
4. What are the common units of measurement for round and square conductor cross - sections?
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
Circular and square mills(Both A and B)
DC current
Current change in a coil creates a magnetic change
5. What types of protective tapes are used?
Voltage
DC flows continuously in one direction and AC potential difference and current both change direction
Potential difference
Plastic - Rubber - Friction(all of the above)
6. What is the unit of measurement of potential difference?
Volts
First digit is 9
Chemical action
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
7. What is the basic law of magnetic force?
Strength of the charge
Purging
Unlike poles attract
Does not move
8. Which way is the current going in the circuit shown?(electron flow)
From the negative battery terminal to the positive terminal
Stores electrical charge
1/1000th of an inch
How much potential difference can a material withstand before breaking down
9. Solve the equation: 35 volts / 0.70 amperes= ? ohms - to find resistance.
Ohms
50 Ohms
Bare - covered - insulated - stranded - cable(All of the above)
Current flows in one direction - potential differences across a load does not change(Both A and B)
10. What does resistance produce?
Heat
Does not move
Parallel
Cells can be connected together to make a battery
11. Which type of cell can be recharged?
Voltage
Bare - covered - insulated - stranded - cable(All of the above)
Secondary cell
Two
12. What is 'difference in potential(potential difference) - per unit of charge - between two points'?
Voltage
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
The relationship of potential difference to current
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
13. What is a DC circuit characteristic?
Current flows in one direction - potential differences across a load does not change(Both A and B)
Composition of the resistor
Potential difference
Voltage
14. What type of circuit has one path of follow through a load?
A magnetic field
1/1000th of an inch
Strength of the charge
Series circuit
15. What is a rigid metal conduit?
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
The direction of the magnetic field
Volts
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
16. What is the type of cable composed of many fine wires?
50 Ohms
The direction of the magnetic field
Stranded
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)
17. How do static charges distribute themselves?
High resistance
Alternating current
Evenly over the surface of a sphere and concentrated on points of objects(both A and C)
1/1000th of an inch
18. What is needed for electric heating elements and the filaments of light bulbs?
Strength of the charge
High resistance
How much potential difference can a material withstand before breaking down
Porcelain
19. What is the unit of measurement of resistance?
--^V^V^V^---
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Mutual induction
Ohms
20. What do electrical charges need to cause a fire or explosion?
Voltmeter
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
A difference in potential energy
Relay
21. The generator is what method of creating potential energy?
Energy
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
10%
Electromagnetism
22. What is a wire classification?
Parallel
Relationship between current and potential difference
Breakdown voltage
Bare - covered - insulated - stranded - cable(All of the above)
23. 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)
75 Ohms
Insulation resistance
First digit is 9
24. If the fourth color band is silver - this means the measured value of the resistance is what percent of the marked value?
First digit is 9
10%
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
Cell
25. What information do the Left-Hand Rules provide?
The direction the negative charge moves
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
A magnetic field
Voltmeter
26. Identify the general blueprint symbol for inductors.
Symbol
Breakdown voltage
15 -000 ohms - 20%
12 volts
27. What is capacitance in electrical terms?
Ability to store an electric charge
The direction the negative charge moves
12 volts
Resistance increases as the conductor length increases
28. What is a type of mechanical transducer?
Circular and square mills(Both A and B)
Porcelain
DC flows continuously in one direction and AC potential difference and current both change direction
Solenoid and Relay(both A and B)
29. What is the use of the electromagnet?
75 Ohms
American wire gauge(AWG)
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
Symbol
30. What is the purpose of capacitors in electrical circuits?
Electrical resistance against the flow of current
Cell
Common - not rechargable - gradually discharges when in storage(All of the above)
Stores electrical charge
31. What is the term for doing work at the rate of joule per second?
1 watt
Current change in a coil creates a magnetic change
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Serial
32. When reading resistance color codes - what does the fourth band indicate?
Alternating current
Opposes any change in the current flowing in a circuit
Tolerence
15 -000 ohms - 20%
33. If the fourth color band is gold - this means the measured value of the resistance is what percent of the marked value?
Evenly over the surface of a sphere and concentrated on points of objects(both A and C)
High resistance
5%
Silver
34. Which of the following materials is NOT a good conductor?
Battery
Porcelain
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)
10
35. What is the fundamental property of insulators?
High resistance
10%
Insulation resistance and Dielectric strength(Both A and B)
Composition of the resistor
36. What is the unit of measurement of electrical current?
Symbol
Amperes
Potential difference - E*I - current times current change from point to point(all of the above)
Opposes any change in the current flowing in a circuit
37. What makes electrons flow?
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Serial
Potential difference
38. How is the heat production measured in a resistor?
Composition of the resistor
Symbol
The relationship of potential difference to current
Potential difference - E*I - current times current change from point to point(all of the above)
39. What is power?
Battery
The rate of doing work
Heat and current control(both a and c)
Magnetic properties
40. Which material has the lowest resistance at ordinary temperatures?
DC flows continuously in one direction and AC potential difference and current both change direction
12 volts
Electromagnetic field
Silver
41. What is the relationship between cells and batteries?
10%
Strength of the charge
Cells can be connected together to make a battery
Alternating current
42. How is capacitance determined?
Area and spacing of capacitor - static current in the capacitor(both A and B)
The relationship of potential difference to current
Magnetic properties
Gauge number
43. Identify the blueprint symbol for resistors.
--^V^V^V^---
Magnetic properties
Serial
Parallel
44. What does a transformer transform?
Start with the band on the end and read to the center
The relationship of potential difference to current
Potential difference
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)
45. What is the relationship of conductor size and length to resistance?
10%
First digit
Amperes
Resistance increases as the conductor length increases
46. What do junction boxes protect?
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)
Secondary cell
Parallel circuit
Wire splices
47. What is voltage?
A difference in potential energy
Choke
15 -000 ohms - 20%
From the negative battery terminal to the positive terminal
48. What do we call the ability to do work?
Energy
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
Insulation resistance and Dielectric strength(Both A and B)
Symbol
49. What is the purpose of resistors in electrical circuits?
15 -000 ohms - 20%
Produce heat - light - or limit current to control it(all of the above)
DC current
Magnetic properties
50. What is a switch that operates by electricity?
Relay
By their covering
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
Secondary cell