Test your basic knowledge |

DC Theory

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. The longer the conductor - the greater the...
Less than the resistance of either resistor.
Compound-wound and shunt-wound.
Until the victim receives medical attention.
Resistance.

2. Current is measured with a (an)...
Ammeter.
Ohmmeter.
Voltage.
It must prevent ignition of surrounding methane atmosphere.

3. The armature of a direct current motor - when running - generates...
A counter-EMF.
Voltage.
Series-wound.
Current that flows in one direction only.

4. What voltage would be required to force 10 amps through a 20-ohm resistor?
200 volts
4.0 ohms.
746 watts.
Current that flows in only one direction.

5. What is the total resistance of three 16-ohm resistors connected in series?
48 ohms.
Clean water.
Current
Ohms.

6. Power is measured with a...
In series.
Flush the burn the clean water.
It must prevent internal explosions.
Wattmeter.

7. Define resistance...
Series-wound.
A bi-directional device that can pass current in either direction.
48 volts
The opposition to flow of electrons in a circuit.

8. What is the flow of electrons in a conductor?
No.4 AWG.
Stays the same.
Treat for physical shock.
Current.

9. Which current flows in only one direction?
500 volts.
Watts.
Direct current.
Attract each other.

10. How long should treatment for shock be continued?
96 volts.
Current
500 volts.
Until the victim receives medical attention.

11. If the victim of an electrical shock has been burned while in contact with electricity - the first treatment you should apply - if the victim's heart and respiratory system are still functioning - is to...
Treat for physical shock.
A wire wound resistor.
It must prevent ignition of surrounding methane atmosphere.
Ohmmeter.

12. Unlike poles of a magnet will...
Watts.
Soft iron.
75 volts.
Attract each other.

13. In a parallel circuit...
400 ampere-hours.
Attract each other.
Resistance.
A. Total resistance is less than the smallest resistor.

14. What is the rate that work is done or heat is dissipated?
Repel each other.
Amperes.
Voltmeter.
Power.

15. When should water be added to a battery?
After charging
Burns will appear only at the point where contact is made to the energized circuit.
Current
15 minutes.

16. The explosive gas that is generated when a battery is charging is...
Flush thoroughly with water.
75 volts.
Hydrogen.
1.260 to 1.280.

17. What is the total voltage of eight 12-volt batteries connected in series?
200 volts
96 volts.
Better speed control on motors.
Resistance.

18. You have three 9-volt batteries. How should you connect them in order to supply 27 volts?
Current that flows in only one direction.
In series.
Ammeter.
The opposition to flow of electrons in a circuit.

19. Which of the following motors are considered to be constant or nearly constant speed?
Compound-wound and shunt-wound.
Flush the burn the clean water.
Current
Soft iron.

20. The instrument used to check the electrolyte of a battery is a...
746 watts.
Hydrometer.
8 ohms.
Watts.

21. Which of the following motors CANNOT be run without a load?
Resistance.
Direct current.
Series-wound.
No.4 AWG.

22. Which of the following is a requirement of an explosion-proof enclosure?
Higher current with voltage remaining the same.
It must prevent ignition of surrounding methane atmosphere.
Ohms.
15 minutes.

23. The unit of measurement of resistance is?
Until the victim receives medical attention.
Ohms.
Distance.
48 volts

24. The advantage of DC over AC is that DC offers...
A bi-directional device that can pass current in either direction.
Hydrogen.
Better speed control on motors.
8 ohms.

25. Batteries connected in parallel provide...
Stays the same.
Less than the resistance of either resistor.
Stays the same.
Higher current with voltage remaining the same.

26. Not true about electrical shocks?
Hydrogen.
Burns will appear only at the point where contact is made to the energized circuit.
Flush thoroughly with water.
It must prevent ignition of surrounding methane atmosphere.

27. Not an electro-magnet?
200 volts
Until the victim receives medical attention.
A wire wound resistor.
Power.

28. What is the equivalent resistance of an 8-ohm and a 12-ohm resistor connected in parallel?
4.8 ohms
15 minutes.
Current.
Amperes.

29. What is the total voltage of four 12-volt batteries connected in series?
48 volts
200 volts
Watts.
Series-wound.

30. If the cross-sectional area of a conductor is increased - its resistance will...
Decrease.
Resistance.
Higher current with voltage remaining the same.
37.3 kilowatts

31. Not a requirement of an explosion-proof enclosure?
A counter-EMF.
100 ohms
It must prevent internal explosions.
6 volts.

32. Voltage in a parallel circuit...
Stays the same.
Until the victim receives medical attention.
A wire wound resistor.
Better speed control on motors.

33. What is the hazard of pouring water into battery acid 'electrolyte'?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

34. The unit of measurement of power is...
15 minutes.
In series.
Watts.
4.8 ohms

35. Like poles of a magnet will...
Repel each other.
Ammeter.
36 volts.
E=IR.

36. A triac is?
Repel each other.
A bi-directional device that can pass current in either direction.
Higher current with voltage remaining the same.
Power.

37. What is Ohm's Law?
The movement of electrons in a circuit.
E=IR.
200 volts
Direct current.

38. What must be provided at underground battery charging stations?
Current
36 volts.
Resistance.
Ventilation.

39. The dangerously explosive gas emitted by charging a lead-acid storage battery is...
No.4 AWG.
Hydrogen.
Treat for physical shock.
36 volts.

40. Define direct current...
4.8 ohms
Current that flows in only one direction.
The opposition to flow of electrons in a circuit.
100 ohms

41. Which of the following stays the same in all parts of a series circuit?
Current
746 watts.
Higher current with voltage remaining the same.
Heat

42. The specific gravity of the electrolyte of a fully charged battery should be...
1.260 to 1.280.
Direct current.
Better speed control on motors.
Voltmeter.

43. Trailing cable on DC-powered mobile haulage equipment must be at least...
A bi-directional device that can pass current in either direction.
In series.
60 ohms.
No.4 AWG.

44. Define direct current...
Series-wound.
Current that flows in one direction only.
In series.
Current that flows in only one direction.

45. The core of an electro-magnet should be made of...
Soft iron.
48 volts
Ammeter.
8 ohms.

46. Storage battery charging stations must be provided with what kind of current protection?
4.0 ohms.
400 ampere-hours.
Reverse.
100 ohms

47. What should be used in treating an eye injury caused by battery acid?
1.260 to 1.280.
Attract each other.
Clean water.
The movement of electrons in a circuit.

48. How many watts are in one horsepower?
48 ohms.
A bi-directional device that can pass current in either direction.
Ventilation.
746 watts.

49. How many kilowatts are used to develop 50 horsepower?
Resistance.
37.3 kilowatts
In series.
48 volts

50. What voltage would be required to force 10 amps through a 50-ohm resistor?
Clean water.
500 volts.
Higher current with voltage remaining the same.
Distance.