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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 do electrical charges need to cause a fire or explosion?
Ability to store an electric charge
Unlike poles attract
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
How much potential difference can a material withstand before breaking down
2. What is a characteristic of insulators?
High dielectric and mechanical strength - tempurature and moisture resistance - flexible(All of the above)
Insulation resistance
Ohms
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
3. What does a transformer transform?
Cell
Potential difference
The relationship of potential difference to current
Alternating current
4. What is a way to classify wires and cables?
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)
By their covering
--^V^V^V^---
DC flows continuously in one direction and AC potential difference and current both change direction
5. What is voltage?
Chemical action
Tolerence
The direction the negative charge moves
A difference in potential energy
6. What is a common cause of static electricity in a shop?
Direction of: electric charge - magnetic field - force of the moving charge(all of the above)
Chemical action
Moving vehicles
Electromagnetic field
7. Identify the blueprint symbol for resistors.
Potential difference
12 volts
Cables
--^V^V^V^---
8. If the fourth color band is silver - this means the measured value of the resistance is what percent of the marked value?
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Opposition to movement of free electrons
Start with the band on the end and read to the center
10%
9. What does Ohm's Law represent?
15 -000 ohms - 20%
Relationship between current and potential difference
By their covering
Solenoid and Relay(both A and B)
10. What is the term for two or more cells attached together?
Battery
High dielectric and mechanical strength - tempurature and moisture resistance - flexible(All of the above)
Cell
Resistance increases as the conductor length increases
11. What is a switch that operates by electricity?
Relay
Battery
High resistance
Resistance increases as the conductor length increases
12. What is the purpose of capacitors in electrical circuits?
Stores electrical charge
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
75 Ohms
Wire splices
13. How do static charges distribute themselves?
Purging
Evenly over the surface of a sphere and concentrated on points of objects(both A and C)
Ohms
Parallel
14. How is the heat production measured in a resistor?
Potential difference - E*I - current times current change from point to point(all of the above)
DC current
Stores electrical charge
A difference in potential energy
15. What types of protective tapes are used?
Plastic - Rubber - Friction(all of the above)
Potential difference
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
Electrical resistance against the flow of current
16. What must be large enough to carry the largest current likely to occur?
Grounding wire
Lifting devices - chucks and clutches - brakes and pulleys(all of the above)
Electromagnetism
Insulation resistance and Dielectric strength(Both A and B)
17. How are the capacitors connected when the combined capacitance equals a sum of all the capacitors?
Parallel
--^V^V^V^---
Series circuit
Ohms
18. The generator is what method of creating potential energy?
Electromagnetism
Alternating current
10%
By their covering
19. What cannot be transformed to higher or lower potential differences?
A difference in potential energy
Chemical action - electromagnetism - contact - heat - light - deformation(all of the above)
DC current
Wire splices
20. What is insulation resistance?
Electrical resistance against the flow of current
Composition of the resistor
Cell
1/1000th of an inch
21. What is the unit of measurement of resistance?
Ohms
Symbol
The rate of doing work
Two
22. What is the purpose of resistors in electrical circuits?
Produce heat - light - or limit current to control it(all of the above)
Amperes
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)
Resistance increases as the conductor length increases
23. What is induction?
Symbol
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Current change in a coil creates a magnetic change
First digit
24. What is power?
Purging
Stores electrical charge
The rate of doing work
First digit
25. What is an arrangement of materials that create a potential difference by chemistry?
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Voltmeter
Cell
26. To what measurement do the conductor mills refer?
Area and spacing of capacitor - static current in the capacitor(both A and B)
10
1/1000th of an inch
Potential difference
27. What is the relationship of conductor size and length to resistance?
Stranded
Resistance increases as the conductor length increases
10%
Does not move
28. What is the type of cable composed of many fine wires?
Heat
Stranded
The direction the negative charge moves
Common - not rechargable - gradually discharges when in storage(All of the above)
29. What is a conductor?
Strength of the charge
A material capable of carrying an electric current Silver - Copper - and Aluminum(Both A and C)
Gauge number
Potential difference
30. What is a rigid metal conduit?
Bonding and grounding
How much potential difference can a material withstand before breaking down
Physical protection for conductors - Grounding for conductors - Concealment for conductors(all of the above)
Moving vehicles
31. What does an object have if a magnetic field acts on it?
Magnetic properties
Heat and current control(both a and c)
10%
Parallel
32. What is the fundamental property of insulators?
Cables
12 volts
Insulation resistance
Insulation resistance and Dielectric strength(Both A and B)
33. What do we call the process of replacement of vapor above a liquid with a nonflammable gas?
Composition of the resistor
Resistance increases as the conductor length increases
Purging
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)
34. What is needed for electric heating elements and the filaments of light bulbs?
Unlike poles attract
By their covering
Cells can be connected together to make a battery
High resistance
35. What is a property of inductors in electrical circuits?
Tolerence
Opposes any change in the current flowing in a circuit
Area and spacing of capacitor - static current in the capacitor(both A and B)
Alternating current
36. What is a common measure of wire diameter?
Area and spacing of capacitor - static current in the capacitor(both A and B)
Symbol
Gauge number
From the negative battery terminal to the positive terminal
37. 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)
Bonding and grounding
Chemical action
Area and spacing of capacitor - static current in the capacitor(both A and B)
38. Where do the fingers point in both Left-Hand Rules?
Choke
Two
Composition of the resistor
The direction of the magnetic field
39. What is the unit of measurement of electrical current?
Two
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)
Resistance increases as the conductor length increases
Amperes
40. What is an electromagnet?
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
When current starts and stops flowing - when an inductor is in the circuit(Both A and B)
Does not move
Cables
41. What makes electrons flow?
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
Current flows in one direction - potential differences across a load does not change(Both A and B)
Potential difference
First digit
42. What is the measure of potential difference?
Gauge number
12 volts
Volts
Ability to store an electric charge
43. Which way is the current going in the circuit shown?(electron flow)
Series circuit
Plastic - Rubber - Friction(all of the above)
From the negative battery terminal to the positive terminal
Ability to store an electric charge
44. How do you read resistor color codes?
Relationship between current and potential difference
Start with the band on the end and read to the center
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
American wire gauge(AWG)
45. What is a type of mechanical transducer?
1 watt
50 Ohms
A coil of wire that: carries current - has a magnetic field inside - and can have a bar of steel inside
Solenoid and Relay(both A and B)
46. Identify the general blueprint symbol for inductors.
Symbol
50 Ohms
Cables
Two
47. Given E=I X R and the following information - plug in the data and solve the problem for voltage. 0.015 ohms - 800 amps of current
12 volts
To prevent Physical - Chemical to wiring - to prevent damage to people and property(all of the above)
Opposition to movement of free electrons
Evenly over the surface of a sphere and concentrated on points of objects(both A and C)
48. What is the difference between AC and DC?
Parallel
Electromagnetic field
DC flows continuously in one direction and AC potential difference and current both change direction
5%
49. What is resistance in electrical terms?
Opposition to electrical current
Potential difference
Energy
Means to maintain a potential difference - means to generate spark - spark in a flammable atmosphere(all of the above)
50. When reading resistance color codes - what does the first band indicate?
Opposition to movement of free electrons
5%
First digit
Potential difference