Midterm

Question 0

What is voltage?

Answer 0

The amount of electrical pressure that causes electrons to move in a circuit.

Question 1

What is a alternating current?

Answer 1

A current that reverses its direction of flow at regular intervals.

Question 2

What is a contact?

Answer 2

The conducting part of a switch that operates with another conducting part to complete(close) or break(open) a circuit.

Question 3

What is an open circuit?

Answer 3

A circuit having an incomplete path, which prevents current flow.

Question 4

What is a closed circuit?

Answer 4

The presence of a completed path for current flow.

Question 5

What is a short circuit?

Answer 5

A undesirable, low resistance path for current to leave the normal current carrying path through a load.

Question 6

What is arcing?

Answer 6

The discharge of an electric current across a gap.

Question 7

What is a series circuit?

Answer 7

A circuit that has two or more components connected such that there is only one path for current flow.

Question 8

What is a conductor?

Answer 8

A material that has little resistance and permits electrons to move through it easily.

Question 9

What is an inverter?

Answer 9

A device that changes dc voltage into ac voltage of any frequency.

Question 10

What is a rectifier?

Answer 10

A electrical component that converts ac to dc by allowing voltage and current to move in only one direction.

Question 11

What is the frequency of electricity in the US?

Answer 11

60hz

Question 12

What is transient voltage?

Answer 12

Temporary undesirable voltage spike, ranging from a few volts to several thousand volts and lasting a few micro sends up to several milliseconds.

Question 13

What is a solid state device?

Answer 13

A electronic component that switches or controls the flow of current in a circuit with no parts.

Question 14

What is a insulator?

Answer 14

A material that has high resistance

Question 15

What is a Overcurrent Protection Device(OCPD)?

Answer 15

A device that automatically opens a circuit to prevent damage from a high-current condition?

Question 16

What is Direct Current(DC)?

Answer 16

Current that flows in one direction only.

Question 17

What is an atom?

Answer 17

The smallest building block of matter that cannot be divided into a smaller unit without changing its basic character. Consist of protons, neutrons, and electrons.

Question 18

What is a current? What is it measured in?

Answer 18

The flow of electrons through a conductor. Measured in amperes.

Question 19

What is resistance? What is it measured in?

Answer 19

The opposition to the flow of electrons. It is measured in Ohms.

Question 20

What is a parallel circuit?

Answer 20

A circuit that has two or more components connected such that there are multiple paths for current flow.

Question 21

What is a ground circuit/line?

Answer 21

Conducting connection between electrical equipment and the earth.

Question 22

What is a relay?What does it do?

Answer 22

A electrical switch that is actuated by a separate circuit. It allows a low voltage control circuit to open or close contacts in a high voltage load circuit.

Question 23

What is a thermocouple?

Answer 23

A device that produces electricity when two different metals are joined together are heated.

Question 24

What is an air handler?

Answer 24

A device used to distribute conditioned air to spaces in a building.

Question 25

What is supply air?

Answer 25

The mixture of outside air and return air that is conditioned for use in a building.

Question 26

What is a pneumatic operator?

Answer 26

A device that uses air pressure to position HVAC components.

Question 27

What do HVAC systems contain?

Answer 27

Heating elements, refrigeration systems,and air handlers.

Question 28

What is a damper?

Answer 28

A movable plate that controls airflow.

Question 29

What is Indoor air quality?

Answer 29

A description of the type and quantity of contaminants in indoor air.

Question 30

What can contribute to Indoor Air Quality(IAQ )problems?

Answer 30

Poorly designed, maintained, and installed HVAC systems.

Question 31

What is a cooling coil?

Answer 31

A finned heat exchanger that removes heat from air.

Question 32

What is Variable Air Volume(VAV) box?

Answer 32

A terminal unit that varies the amount of air flowing into a zone.

Question 33

What is short cycling?

Answer 33

The increase in the frequency of system operation due to improper feedback.

Question 34

What is a work order?

Answer 34

A document that details specific maintenance task to be completed.

Question 35

What is preventative maintenance?

Answer 35

Scheduled work required to keep equipment in peak operating condition.

Question 36

What is inventory control?

Answer 36

The organization and management of commonly used parts, vendors and suppliers, and purchasing records in the PM system.

Question 37

What is a reactive hazard?

Answer 37

The degree of susceptibility of materials to explode or release energy by themselves or by exposure to certain conditions or substances.

Question 38

What is a physical hazard?

Answer 38

A hazard caused by excessive levels of noise, vibration, illumination, temperature, of the ladder.

Question 39

What is hazardous material?

Answer 39

A substance that could cause injury to individuals or damage to the environment.

Question 40

What can be an air contaminate?

Answer 40

Dust, fumes, aerosols, fibers.

Question 41

What is required to start and sustain a fire.

Answer 41

Fuel, heat, and oxygen, also chemical agents.

Question 42

What is a regulation?

Answer 42

A rule made mandatory by a federal, state, or local government.

Question 43

What is a code?

Answer 43

A collection of regulations related to a particular trade or environment.

Question 44

What is a standard?

Answer 44

A collection of voluntary rules developed through consensus and related to a particular trade, industry, or environment.

Question 45

What is a flow chart used for?

Answer 45

To help a troubleshooter follow a logical path when solving a problem.

Question 46

What is sensible heat?

Answer 46

Heat energy that can be measured by a change in temperature.

Question 47

What is latent heat?

Answer 47

Heat energy that causes a change of state but no change in temperature.