MIJ

[Four-way switch Symbol]

Four-way switch

[Fuse Symbol]

Fuse

[Ground Symbol]

Ground

What must be done secondary of a transformer?

Ground the secondary

The circuit breaker uses two principal of operation to protect a circuit

Heat and Magnetism.

[Horn Symbol]

Horn

Horsepower

How an electric motor is rated

Insulator:

Impedes the flow of electrons

What effect does inductive reactance have on capacitive reactance?

Inverse Proportionality as inductance increases reactance decreases and visa - versa.

Transformers are rated in

KVA.

KCM

Kilo Circular Mils

When the power factor is other than unity, it may be either

Lagging or Leading.

[Lamp Symbol]

Lamp

What is done to secondary of a transformer including delta secondary?

Must be grounded.

Are thee any limitations in installing a conduit run of 4" galvanized pipe? If so, what are they?

Not more than four 90 degree bends or a total of 360 degree within 100 feet.

An autotransformer has

One winding

A capacitor acts as a(n) _________ (open/closed) circuit for DC.

Open

A capacitor acts as an________ for DC.

Open Circuit

A 2000 watt heater draws 8 amps. What is its rated voltage? Show all work

P = Ex 1 ————— E = P/I = 2000/8= 250 volts

PNP

Positive negative positive — referring to transistors

You are to run conduit to be placed directly against a pl in a wet location, what is acceptable?

rigid non-metallic conduit rigid metallic conduit

Factors to be considered in the section of a voltage system are

size of the building, nature of occupancy, size of load and type of load.

Impedance

the vector sum of the inductive and capacitive reactance, which describes the opposition to the flow of current in AC circuit.

Efficiency of a motor is - efficiency = HP x 746 / Watts x 100

true

In a balanced 3-wire single phase system, the neutral conductor carries _____ percent of the phase conductors.

0

You have a 100v source feeding a 100w lamp, what is the draw?

1 amp

A resistor draws 12 amps and has a resistance of 10 ohms. How much power does it consume?

1,440 Watts (P = 12R)

What is the value of X in the following equation: 45X=120/2 Show each step.

1.33

12/156 is equal to

1/13

A circuit has an operating voltage of 220 volts. The circuit resistance is 55 ohms which limits the current to 4 amperes. You wish to add enough resistance to limit the current to 2 amperes. How much total resistance would you need in this circuit?

110 ohms

It takes ______ 1.5-volt batteries to power an 18-volt load.

12

The phases of a three phase transformer are by _____________ (degrees)

120 degrees.

You receive a delivery of 1500 light fixtures, by the end of the week, only 300 are not installed. You can submit a request for what percentage?

1500 - 300 = 1200, 1200 / 1500 = 0.8 = 80%

A 2000 watts heater draws 8 amps. What is the rate voltage?

250V (E = P//I).

How many current carrying conductors are required for secondary?

3

A 180 volt circuit has a resistance of 4.5 ohms. How much power is consumed? Show our answer in kw.

3.2kw

On a drawing using 4"= 1'. How large will a room that measures 17'6"x 22'?

4 3/8" x 5 " (17'6" = 17.5, 17.5/4= 4.375) ( 22 / 4 = 5.5)

You have a straight conduit run of 3 and 4, what dimensions of the pull box?

4 x 8 = 32 min length [NEC 99 article 370-28P Junction boxes (a) (1)]

You need a pull box for a straight pull in a 4" conduit. How long a pull box is required by code?

4" x 8 = 32"

Use the law of proportionality to solve for the voltage across R1 in the following circuit.

4.8 volts

maximum number of circuit breakers in a panel?

42

A 20-ohm resistor is placed across a 120-volt source of supply. The wattage consumed by the circuit is _______ watts.

720

A rating of one horsepower is equal to________

746 Watts.

One horsepower is equal to_______w.

746 watts

One angle of a right triangle is always a(n)_ degree angle.

90

Manual control

A controller controlled by manual means

Capacitor

A device made with two metal plates and a dielectric between that stores electrons.

Autotransformer

A transformer that uses only one winding for both primary and secondary.

A Commutator converts

A/C to D/C

How does AC differ from DC?

AC changes direction at every half cycle while DC remains constant.

Transformers are cooled by

Air and Oil.

Conductor:

Allows the flow of electrons.

What is meant by a dielectric?

An electric insulator

You would find the dimensions of offices and hallways on the _____________ blue print.

Architectural

The information on a door swing can be found on the_____

Architectural floor/ blue plans/ prints

Additive and subtractive polarities refer to

Batteries and battery connections

What is the definition of eddy current?

Circular induced current contrary to the main currents. Eddy currents are a source of heat power loss in magnetically operated devices.

A 120/208v delta is commonly found where?

Commercial buildings, Schools, Factories

An example of a non-linear load is

Computer or electronic variable speed motor control

What does C.E.M.F. stand for?

Counter Electro Motive Force

A series circuit will have the same ______ at each load.

Current

A series circuit will have the same __________ at each lead.

Current

A capacitor is made up of two conductors separated by a____________.

Dielectric.

The output of a rectifier

Pulsating Direct Current

What is the formula for calculating the resistance of wire?

R = KxL / A

The motor's speed is measured in

RPM - Revolutions Per Minute

Thermal relays will

Remove power to the motor

There is always a ________ angle in a right triangle.

Right

The total resistance of a parallel circuit is always ______ the smallest resistor of the circuit.

Smaller than

[Draw a line diagram of a stop, start station; label all parts.]

Stop Start Station and Parts

The neutral is connected to the__________

Street side of the water main

If a motor control center is located in an electrical equipment room that is otherwise required to be readily accessible means.

The motor control center must not be obstructed. Those that must operate and maintain the equipment must have.

Resistance.

The opposition to current flow

Hertz.

The unit of measurement for the number of cycles per second

Impedance is

The vector sum of inductor, capacitor and resistor, reactances which describe the opposition to the flow of current in an AC circuit.

CEMF

The voltage induced in the armature of a DC motor that opposes the applied voltage and limits armature current.

A variable resistor wired as a potentiometer has _______ leads.

Three

Do not stand on the _______ step of a ladder.

Top

By code, conduit is the smallest size allowable

True

Can a #8 A.W.G. be placed on a 20 amp breaker?

True

The speed of AC machines is easier to adjust than DC machines.

True

The term harmonics has nothing to do with the electrical work.

True

toggle bolts are approved method of anchoring into cinder blocks.

True

A watt meter measures

True Power

To operate a light fixture from five locations, how many 3 Way switches are needed?

Two

To control a light from four locations, it is necessary to install ______ switches.

Two 3-way and two 4-way

True power is represented as watts while apparent power represented as

Volt Amps

In a parallel circuit, the entire ______ is dropped across each load.

Voltage

In a parallel circuit, the entire ___________ is dropped across the load.

Voltage

7. A study of the table of wire insulation is rated in two general areas other than voltage. These are _______ or ____________locations and at not more than a specified_______________

Wet or Dry & Ampacity / Temperature

You are working on a print drawn to a scale of 1/8"-1". A room is 16 feet wide. What would this measure on the print?

X = 2"

Is the neutral conductor the same as the ground conductor?

Yes

Are there any bend limitations in installing a conduit run of 4" galvanized pipe. If so, what are they?

Yes, 360 degrees

The rotating field of a motor is produced by the

armature

Generator

converts mechanical energy into electrical energy.

Magnetic switch control is accomplished by

electromagnetism

Short circuit protection is provided by

fuses and circuit breaker

A motor's output is rated in

horsepower

the energy consumed by a motor is rated in

horsepower

If you reverse direction of current flow through coils of wiring, the direction of the coil will reverse the

magnetic field