3 Basic Electricity

Question 1

1. One kilowatt is equal to how many watts?

Answer 1

1000

Question 2

2. What law describes the most fundamental or basic relationships in an electrical circuit?

Answer 2

Ohm’s Law.

Question 3

3. What are the 3 elements of Ohm’s Law?

Answer 3

Voltage, current, and resistance.

Question 4

4. How would you write Ohm’s Law as an equation?

Answer 4

E=IR, R=E/R, I=E/R

Question 5

5. If the resistance in a DC circuit remains the same but the voltage doubles, what happens to the amount of current flowing in the circuit?

Answer 5

It also doubles.

Question 6

6. In DC circuits, what unit measures power?

Answer 6

Watts

Question 7

7. What 3 elements are required to form an electrical circuit?

Answer 7

A source of electrical energy, a load or resistance to use the electricity, and wires or conductors to connect the source to the load.

Question 8

8. DC circuits can take 1 of 3 forms or types, what are they?

Answer 8

Series, parallel, complex

Question 9

9. A 24V lead acid battery has how many cells?

Answer 9

12

Question 10

10. A fully charged lead acid battery has a specific gravity that varies between what 2 values?

Answer 10

1.275 and 1.300

Question 11

11. You must apply a correction to the specific gravity reading of the electrolyte of a lead acid battery when the temp is outside of what 2 values?

Answer 11

Below 70 degrees or above 90 degrees.

Question 12

12. What is the reason for having separate facilities for storing and servicing nickel cadmium and lead acid batteries?

Answer 12

The electrolyte in the 2 types of batteries is chemically opposite and the fumes from one type can contaminate the electrolyte of the other type.

Question 13

13. The state of charge of a nickel cadmium battery can’t be determined by measuring the specific gravity of the electrolyte for what reason?

Answer 13

There is no significant change in the specific gravity of the electrolyte as the battery is charged or discharged.

Question 14

14. What is the principal advantage of AC current over DC current?

Answer 14

Power can be transmitted over long distances more efficiently and with smaller wires because the voltage can be easily increased or decreased by a transformer.

Question 15

15. What are the 3 causes of opposition to current flow in an AC circuit?

Answer 15

Resistance, inductive reactance, and capacitive reactance.

Question 16

16. Define inductance.

Answer 16

An induced voltage which is opposite in direction to the applied voltage.

Question 17

17. What component creates capacitance in AC circuits?

Answer 17

A capacitor.

Question 18

18. How does a capacitor store electricity?

Answer 18

The energy is stored in the form of an electrostatic charge or field that exists between 2 conductors separated by an insulator.

Question 19

19. What property of an AC circuit is defined by the term impedance?

Answer 19

The total opposition to current flow.

Question 20

20. What are 2 reasons that might cause a nickel cadmium battery to fail to deliver its rated capacity?

Answer 20

Faulty cells or cell imbalance.

Question 21

21. What electrical values are measured by a typical multimeter?

Answer 21

Voltage, current, and resistance.