TEC100 Electricity - Final

T/F: The main characteristic of static electricity is that a prolonged or steady flow of current is not possible.

True

T/F: In the basic warm-air furnace, many controls that are applicable to warm-air furnaces depend on the type of energy that is being used to supply the heat to the structure

False

T/F: The simplest atom that exists is the hydrogen atom, which consists of one proton that is orbited by several electrons.

False

T/F: An electrode is a solid conductor through which an electric Current can pass

True

T/F: The electrons flowing in an electric circuit are referred to as current

True

T/F: A packaged air conditioning unit is manufactured in one piece with all the components, including the thermostat.

False

T/F: Contactors are rated by the ampere draw they can carry

False

T/F: Thermal overload devices operate by magnetism

False

T/F: In all types of forced-air heating equipment, there must be some method of controlling the fan motor so that the warm air is delivered to the condition space at the correct temperature

True

T/F: A conductor is a material that does not take on electrons

False

T/F: An insulator is a material that has free electrons available

False

T/F: Steam is the most popular method of transferring heat from an appliance to a structure

False

T/F: Electrical shock occurs when a person becomes part of an electrical circuit

True

T/F: Do not use metal ladders when working near live electrical circuits

True

T/F: An electric meter is a device used to measure some electrical characteristic of a circuit

True

T/F: Relays cannot be used to open and close a control circuit

False

T/F: The contractor contacts must be in good condition to ensure that the proper voltage reaches the load

True

T/F: The schematic diagram is the most useful and easiest to follow of any electrical diagram

True

T/F: The clamp-on meter uses the device being checked as the load to produce a magnetic field

False

T/F: An electric circuit is the complete path of an electric current, along with any necessary elements, such as a power source and a load

True

T/F: The most common device supplied with energy is an electric motor

True

T/F: Magnetism can only be produced by the earths core

False

T/F: Loads are devices, such as motors, solenoids, resistance, heaters, and other current-consuming devices

True

T/F: The central part of an atom is called the nucleus

True

T/F: A contactor is used to control an electric load in a control system

True

T/F: The resistance-start induction-run motor has only a starting winding

False

T/F: One of the most important tasks that a service technician must learn is how to safely work around equipment when the power is being supplied to the equipment

True

T/F: Most electric meters are capable of reading more than one electrical characteristic

True

T/F: Contacts are made of silver and cadmium, which resist sticking

True

T/F: A heat pump is an air-conditioning system that uses a reversing valve to reverse the refrigeration cycle in order to provide heating

True

T/F: An alternating current motors speed is determined by the frequency of the power supply only

False

T/F: A solenoid is not considered to be a load because it consumes very little electricity

False

T/F: The schematic wiring diagram uses photos to represent electrical components in the system

False

T/F: A permanent magnet is a piece of magnetic material that has been magnetized and can hold its magnetic strength for a reasonable length of time

True

T/F: Fuses cannot be used to protect wires and non-inductive loads, but they provide adequate protection for inductive loads

False

T/F: An electron has a positive charge, while a proton has a negative charge

False

T/F: Most electrical systems and equipment or control systems use either parallel or series circuits

False

T/F: Normally open contacts open and normally close contacts close when the relay or contactor is energized

False

T/F: An alternating current of 60 Hertz changes direction 100 times per second

False

T/F: The differences among the various electric meters, except for digital meters, are not in the meter movements, but in the internal circuits of the meter, and in how the magnetic fields are created

True

T/F: Contactors make or break a set of contacts that controls the voltage applied to some load in cooling systems

True

T/F: Most residential and small commercial installations use a 12 Volt control system

False

T/F: When assisting a person who is in contact with an electrical source, it is generally safe to touch him or her

False

T/F: The transformer for a residential unit is used to convert line voltage to 24 Volts

True

T/F: All magnets have three poles

False

T/F: To make an electric motor move continuously, the magnetic field must rotate

True

T/F: All electric circuits must have a complete path for electrons to float through, a source of electrons, and some electric device (load) that requires electric energy for its operation

True

T/F: The analog meter makes use of ohms law to measure and display the electrical characteristics of a circuit

False

T/F: Coil characteristics depend on the type of wire, but not the manner in which it is wound

False

T/F: The parallel circuit has only one path for the electron flow

False

T/F: The electrical source refers to the electrical energy being supplied to equipment

True

T/F: A stack switch is a heat-actuated control that uses the stack temperature to indicate that the oil burner has or has not established a flame

True

T/F: There are several types of fan switches used in the industry

True

T/F: The schematic diagram resembles a ladder and that it is made up of two vertical lines representing the incoming electrical sources

True

T/F: Motors are selected mainly because of the starting torque required for the motor to perform its function

True

T/F: The total current draw of the entire parallel circuit cannot be determined

False

T/F: The current draw on a parallel circuit is determined for each part of the circuit, depending on the resistance of that portion of the circuit

True

T/F: An atom is the smallest particle of an element that can exist alone or in combination

True

T/F: Motor speed is generally used to classify motors into different types

False

T/F: The basic heating appliance used in the heating and cooling industry, usually heats air or water or produces steam

True

T/F: Energy is the substance of which a physical object is composed

False

T/F: The capacitor consists of two aluminum plates with an insulator between them

True

T/F: Wearing rings, watches, or other jewelry when working in close proximity to live electrical circuits is generally considered a safe practice

False

T/F: A parallel circuit is designed to supply more than one load in the system

True

T/F: The voltage in a series circuit is the same for each device

False

T/F: To obtain an ampere reading, you should clamp the jaws of the meter around two wires

False

T/F: When electricity passes through the body, the results can range from death to a slight, uncomfortable, stinging sensation, depending upon the amount of electricity that passes through the body, the path the electricity takes, and the amount of time that the electricity flows

True

T/F: Motors are used in the industry to rotate compressors, condenser fan motors, pumps, and other device devices that require rotating movement

True

T/F: The intermittent pilot control system must only light the pilot

False

T/F: A series circuit is usually used for devices that are connected in the circuit for safety or control

True

T/F: If the control system is set for heating and the temperature in the structure drops below the set point, the first stage of the heating thermostat opens

False

T/F: The term normally refers to the position of a set of contacts when the device is de-energized

True

A __________ is the smallest particle of a substance that has properties of that substance

Molecule

A __________ is a refrigeration system that is designed to maintain a temperature lower than 32°F in a refrigerated case

Commercial freezer

The __________ has its own power supply and uses the device being checked as the load to produce a magnetic field

Ohmmeter

A load that is purely resistant in nature with no coils to cause induction is called a resistive or __________ load

Non-inductive

The nucleus of an atom is made up of __________ and neutrons

Protons

A __________ is an electric device that protects a load from a high ampere draw by breaking a set of contacts

Overload

The __________ is a cycle of operation of a heat pump that is designed to defrost the outside coil during the heating operation

Defrost cycle

The chemical composition of contacts is such that they operate at cool temperatures of up to __________ % of their current-carrying capacity

125

The three electrical characteristics of a circuit that are most important to industry technicians are __________, amperes, and ohms

Volts

The temperature in any structure, regardless of its age, location, or design, can be maintained at comfortable levels with a __________

Thermostats

The diagnosis of a faulty contactor encompasses three sections of the contactor: the coil, the contacts, and the __________

Mechanical linkage

The __________ fan switch is nothing more than a thermostat that closes on a rise in temperature to start the fan motor when the furnace can supply warm air to the structure

Temperature controlled

Thermostats that are immersed in water are sometimes called __________

Aqua stats

If the North pole of a bar magnet is brought close to the north pole of another bar magnet, they will __________ each other

Repel

The __________ diagram not only identifies the electrical components that are in the unit, but also illustrates how the unit works and electrical connections that need to be made

Schematic

The most commonly used rotor today is the __________ rotor

Squirrel cage

A __________ is a device that permits the connection of a three-prong plug to a two-prong receptacle

Grounding adapter

The __________ overload breaks the power to a motor

Line break

A __________ is a light that is illuminated to denote a certain condition in a system

Signal light

__________ are loads, found in many systems and wiring diagrams that are responsible for taking electric energy and convert it to heat

Heaters

The __________ of an atom orbit around the nucleus

Electrons

Electric __________ is the rate at which the electrons do work

Power

The __________ pilot burns only when there is a call for heating and remains off when there is no call for heat

Intermittent

A __________ is an electric circuit that controls some major load in the system

Control circuit

In a case of ventricular fibrillation, unless the heart is returned to normal quickly, the person will usually __________

Die

A __________ takes the humidity out of air in a specific area

Dehumidifier

The __________ of a control is the point at which the contacts open or close, depending on the function of the control

Set point

The electrical energy supplied to an electrical circuit is called __________, and it is measured in volts

Electromotive force/EMF