Test Review

Question 1

Name two safety rules

Answer 1

Think- think of all the rules concerning safety.

Work with one hand when possible- worst electric shock occurs when the current path is from hand to hand.

Question 2

How many amps does it take to cause death?

Answer 2

0.1-0.2 amps

Question 3

Name the types of PPE.

Answer 3

1. Head protection
2. Eye protection
3. Hearing protection
4. Fire-retardant clothing
5. Gloves
6. Safety harness

Question 4

What is the rule for setting a ladder?

Answer 4

Angle of a ladder is 76 degrees and rise over run 4:1

Question 5

What are the types of electrical sources?

Answer 5

A/C- bidirectional

D/C- unidirectional

Question 6

What is an Atom and what does it consist of?

Answer 6

An atom is the smallest unit of matter. It has in its nucleus a nuetron-nuetral, and a proton-positive. The outside of the nucleus has electrons-negative.

Question 7

What is the outer shell of an atom and its properties?

Answer 7

The outer shell is the valence shell and it contains the valence electrons with no more than 8 in it.

Question 8

What is a conductor?

Answer 8

Is made from a material that permits electrical flow. It has 1-3 electrons in it so it gives them up easily.

Question 9

What is electrical flow?

Answer 9

It is the flow of electrons thru a conductor.

Question 10

What is an insulator?

Answer 10

An insulator is a material that resist the flow of electrons. It has 7 or 8 electrons in its valence shell.

Question 11

What is a semiconductor?

Answer 11

A semiconductor is a material that is neither a good conductor or insulator. It has four valence electrons.

Question 12

Name the methods of producing electricity

Answer 12

1. Magnetism
2. Chemical action
3. Pressure
4. Heat
5. Friction
6. Light

Question 13

What is a coulomb?

Answer 13

A coulomb is a quanity of measure of electrons. It contains 6.25x10 to the 18 electrons.

Question 14

What is a volt?

Answer 14

A volt is the potential difference or electromotive force. (Emf) It is the amount of potential necessary to cause 1 coulomb to produce 1 joule of work. It is the pressure of an electrical circuit.

Question 15

What is an ohm?

Answer 15

It is the unit of resistance to current flow.

Question 16

What is a watt?

Answer 16

A watt is the amount of power used in a circuit. It is the measure of true power

Question 17

What is a permanent magnet?

Answer 17

Are magnets that do not require any power or force to maintain their field.

Question 18

What are magnetic materials?

Answer 18

1. Ferromagnetic material- a metal that is easily magnitized ex. Iron, nickel, cobalt, manganese
2. Paramagnetic material- metals that can be magnitized but not as easily as ferromagnetic metals. Ex. Platinum, titanium, and chromium
3. Diamagnetic material- metal or non metal materials that can’t be magnetized. Ex. Copper, brass

Question 19

What is electromagnetic?

Answer 19

Law that states that whenever an electric current flows through a conductor a magnetic field is formed around the conductor.

Question 20

What determines the number of flux lines by an electromagnetic?

Answer 20

Number of turns of wire and the current flow.

Question 21

What is permeability?

Answer 21

The measure of a materials ability to become magnitized.

Question 22

What is reluctance?

Answer 22

Is the resistance to magnatism.

Question 23

What is saturation?

Answer 23

When all the molecules of the magnetic material are lined up.

Question 24

What is coercive force?

Answer 24

Is the measure of a materials ability to retain magnetism.

Question 25

What is flux density?

Answer 25

In the english system, the measure for magnetic strength

Question 26

How do you demagnetize?

Answer 26

1. Place item in a/c magnetic fields
2. Hit item
3. Heat item

Question 27

What is a variable resistor and name two.

Answer 27

A resistor whose values can be changed or varied. Potentiometer and rheostat.

Question 28

Name the laws of series.

Answer 28

1. The current is the same at any point in the circuit.
2. The total resistance is the sum of the individual resistors.
3. The applied voltage is equal to the sum of the voltage drops across all the resistors.

Question 29

Name the laws of parallel.

Answer 29

1. The total current flow in the circuit is equal to the sum of the currents through all the branches.2. The voltage drop across any branch of a parrallel circuit is the same as the applied voltage.
2. Total resistance of a parrallel Circuit is always less than the resistance of the lowest value resistor.

Question 30

What is cell voltage?

Answer 30

The amount of voltage produced by an individual cell is determined by the materials from which it is made.

Question 31

What is a primary cell?

Answer 31

Is a cell that cannot be recharged. The chemical reaction causes one of the electrode to be eaten away as power is produced. When the cell becomes discharged it should be replaced.

Question 32

Explain current capacity

Answer 32

The amount of current a particular type of cell can deliver is determined be the surface area of its plates

Question 33

What is specific gravity?

Answer 33

Is a measure of the amount of acid contained in the water

Question 34

What is a hydrometer?

Answer 34

A device used for measuring the specific gravity of a cell.

Question 35

Charging cycle info

Answer 35

The terminal voltage of the power supply must be greater than that of the cell or battery. As current flows through the cell, hydrogen is produced at the negative plate and oxygen is produced at the positive plate.

Question 36

What is a thermocouple?

Answer 36

A thermocouple is a device with two dissimilar metals that produce electricity with heat

Question 37

What ia a fixed resistor?

Answer 37

A resistor with only one ohmic value, which cannot be changed or adjusted.