Electrical apprenticeship year 1- exam 2 prep

What's the demand load for ten 5.25 kW dryers installed in dwelling units of a multifamily building?

27 kW

What is the applied voltage in a series circuit with two resistors (25 V and 10 V, respectively)?

35 V

A two-resistor series circuit has an applied voltage of 100 V. The voltage across one of the resistors is 60 V. What is the voltage across the other resistor?

40 V

A series circuit has a total resistance of 240 Ω and a current flow of 4 A. What is the applied voltage?

960 V

A basic law of magnetism states that unlike poles _____ and like poles _____.

Attract; repel

An electric motor is running on 120 V. The current is measured to be 5 A. How many ohms of resistance is the motor?

24 ohms

True or false: The grounding prong of a plug should never be cut off or bypassed.

True

When a circuit has only one path, the _____ is the same at any point.

current

What size single-phase, 3-wire feeder is required for a 110A service of which 36A consist of 240V loads? Size the conductors based on 75°C terminals in accordance with 110.14(C)(1)(b).

Two 3 AWG and one 4 AWG

What's the dwelling unit service neutral load for one 9 kW range?

5.60 kW

Using the optional method for dwelling unit calculations, what's the fixed appliance portion of the 60-unit multifamily building's demand load if each unit has a water heater (4 kW) and a dishwasher (1.50 kW)?

79.20 kVA

Using the optional method, what size service will be required for a two-family dwelling, where each unit is 1,000 sq ft and contains the following loads? The system voltage 120/240V single phase. - Dishwasher 1,100 VA - Waste Disposer 900 VA - Water Heater 4,500 VA - Dryer 4,500W - Range 12,000W - A/C, 13.80A compressor, with 1.20A fan, both at 240V - Heating at 240V 7,500W

A 175A service with 2/0 AWG conductors.

The regions formed in the molecular structure of magnetic metals are sometimes called magnetic _____.

domains

When sizing a feeder for the fixed appliance loads in dwelling units, a demand factor of 75 percent of the total nameplate ratings can be applied if there are _____ or more appliances fastened in place on the same feeder.

four (220.53)

The current, voltage, power, and resistance in a series circuit can be calculated using _____ law.

ohm's

A series circuit has two resistors that dissipate 10 W and 5 W, respectively. What is the total power dissipation of the circuit?

15 W

An electric circuit has a resistance of 40 Ω. The current is measured to be 6 A. How many volts are applied to the circuit?

240 V

A conductor is made from a material that contains between _____ valence electrons.

One and three

A point that is used as a common connection for other parts of a circuit not actually driven into the ground is called a _____ ground.

chasis

The receptacle outlet required for indoor electrical service equipment shall not be required to be installed for _____.

one and two family dwellings (210.64)

If a series circuit has resistor values of 37 Ω, 36 Ω, and 102 Ω, the total resistance is _______________ Ω.

175

The amount of _____ across a resistor is proportional to its resistance.

voltage drop

True or False: A feeder or service dryer load is required even if the dwelling unit doesn't contain an electric dryer.

false

What force pushes the electrons through a resistance in a circuit?

voltage

A series circuit has a total resistance of 180 Ω and an applied voltage of 120 V. What is the current flow?

0.667 A

An electrical circuit has a voltage of 20 V and a resistance of 2 Ω. What is the value of current?

10 A

In a series circuit, the sum of the voltage drops is _____ the applied voltage.

Equal to

In the English system, the total force producing a magnetic field is the _____.

Magnetomotive force

What's the neutral demand load for ten 5 kW dryers?

17.50 kW

The feeder or service neutral load for household cooking appliances, such as electric ranges, wall-mounted ovens, or counter-mounted cooking units, is permitted to be calculated at _____ percent of the load as determined by 220.55.

70

The Code provides rules for the minimum number of receptacle outlets required in a dwelling unit. The minimum required receptacle outlets shall be in addition to receptacle outlets that are _____. A) part of a luminaire or appliance B) controlled by a wall switch for use as required illumination C) located more than 5 1/2 ft above the floor D) all of these

D) all of these (210.52(1), (2), and (4))

Of the three basic classifications of magnetic materials, _______________ materials are either metal or nonmetal materials that cannot be magnetized.

Diamagnetic

Of the three basic classifications of magnetic materials, _______________ materials are metals that are most easily magnetized.

Ferromagnetic

What device is designed to open and disconnect a circuit in the event of excessive current?

Fuse

A voltage _____ is used to provide different voltages between certain points in a circuit.

divider

120V, single phase, 15A and 20A branch circuits supplying outlets and devices installed in guest _____ of hotels and motels shall be protected by any of the means described in 210.12(A)(1) through (6).

rooms and suites (210.12(c))

All 15A and 20A, 125V, single phase receptacles installed in _____ of dwelling units shall have GFCI protection.

unfinished portions or areas of basements not intended as habitable rooms and crawl spaces (210.8(A)(4) and 210.8(A)(5))

A three phase, 4 wire, _____ power system used to supply power to nonlinear loads may necessitate that the power system design allow for the possibility of high harmonic currents on the neutral conductor.

wye connected (210.4(A) note 1)

Using the standard method, what service neutral conductors are required for a twenty-unit multifamily building having the following loads in each 1,000 sq ft unit, where the service conductors are paralleled in two raceways? A separate laundry facility is provided on the premises for the tenants [210.52(F) Ex 1]. The system voltage 120/208V, three-phase. - Dishwasher 1,000 VA - Waste Disposer 900 VA - Water Heater 4,500W - Dryer 4,000W - Range 12,000W - Air-Conditioning (230V), 20A - Electric Space-Heating 6,000W

1/0 AWG

A dwelling unit has 2,330 sq ft of living space. In addition, there's a 900 sq ft porch, and a 400 sq ft carport (not a garage) with the following loads: - Waste Disposer (1 kVA) - Dishwasher (1.50 kW) - Trash Compactor (1.50 kVA) - Water Heater (6 kW) - Range (14 kW) - Dryer (4.50 kW) - Air-Conditioning Unit (5 hp 230V) - Baseboard Heat (Four separately controlled at 2.50 kW each) Use the optional method to determine what size aluminum conductors are required for the 120/240V, single-phase service.

1/0 AWG AL

A three-resistor circuit has a total power of 55 W. Two of the resistors dissipate 40 W and 5 W, respectively. How much power does the third resistor dissipate?

10 W