etrical test prep

what voltage would be found from terminal g to the load said of the transformer

0 volts AW

Which of the following is equal to 100 milliamps

0.10 amperes AW

What voltage would be found across the fuse in line #10 with the thermastat closed

0volts AW

Relays are generally used to control inductive loads up to ____ amps.

10 AW

three ohms reistors are wired parallel the total resistence equals

100 ohms AW

How many watts of power are used by a heater operating at 240 volts and drawing 5 amps

1200 watts

The synchronous speed of a four pole. 60hz single phase motor is

1800 rpm AW

The voltage to ground of a high leg or stinger leg on a three phase open delta system will be approximately

208 AW

Which of the following is equal to 2.1kq

21000n watts AW

IN the schematic that voltage would be found from terminal Y to the output side of the coil on line 11

24 volts AW

in the schematic that voltage would be found from terminal Y to the imput side of the coil on line #11

24 volts AW

A transformer has 1000 turnd of wire in the primary coil and 2000 turns in the secondary coil. if 120 volts are applied the out put voltage will be

240 volts AW

What voltage would be found across the condenser fan motor

240 volts AW

Utility companies usually supply residential homes with ____ service

240V, single phase, three wire AW

in the schematic what voltage would be found across L1 to L2

240volts AW

Three defrost heaters, each 15 ohms are wired in parallel to a 120 volt power supply how many watts of power will be used

2880 watts AW

What is the minimum number of wires required between two start/stop push button controls

3 AW

which of the following is an acceptable temporary replacement for a run capacitor rated at 35MFD

37.5MFS @440VAC AW

which of the following is generally considered to be within the maximum allowable supply voltage variation

5% AW

A parallel circuit contains a 18 ohms and 9 ohm resistor the total resistance =

6 ohms AW

How much resistance must be placed in a 120 volt circuit in order to limit the current to 2 amps?

60 ohms AW

A transformer has 1000 turnd of wire in the primary coil and 500 turns in the secondary coil. if 120 volts are applied the out put voltage will be

60 volts AW

a parrallel circuit consists of three resistors R1=30 ohms R2= 15 ohms R3= 10 homs if the current through R2= 4 amperage what is the source voltage

60 volts AW

one horsepower is equal to ____ watts

746 Aw

The symbol for pressure switch that closes on pressure rise represented by diagram

A AW

An ohmmeter should never be connected to

A charged capacitor until it has been discharged AW

An electron has

A negative charge AW

The symbol for heating thermosyay is reprsented by diagram

B AW

The symbol for pressure switch that opens a pressure rise

C AW

Any material that will readily release electrons is called

Conductor AW

Which of the following statements about current is true

Current flow will increase when voltage increases AW

resistance is calculated by

E devided by I AW

which of the following motors is most energy efficent

ECM AW

A solenoid value operates on the principle of

Electromagnetism AW

Current flow

Flow of voltage in a circuit AW

A typical thermocouple used on a gas furnace can

Generate a small DC electrical current AW

With a motor running at full load, voltmeter leads are placed on L1. and T1 terminals of the contactor. The voltmeter indicates no measurable voltage. This is an indication of?

Good clean contacts AW

The safety ground conductor is usually colour coded

Green or Bare AW

When testing a motor with an ohmmeter, the following measurements are recorded, Common to run 4 ohms, Common to start 6.2 ohms, Run to start 10.2 ohms, and Common to ground 20.4; This indicates of

Grounded condition AW

the capacitor start-capacitor run (cscr) motor provides

High starting and running torque AW

The symbol for current is

I AW

Voltage can be calculated by

I times R AW

When the temperature of a negative temperature coefficent thermistor increases it resistance will

Increase AW

If the conductor in an Ac circuit is wound into a coil, the resulting EMF opposes the supply voltage this opposition is called

Inductive reactance AW

The total resistence of a parallel circuit will be;

Less than the smallest resistance AW

What connects the terminals T1, T2, T3 on a contractor motor starter

Load connections AW

When testing a capacitor with an analog or digital ohmmeter, the meter should?

Measure low resistance then return to a high reading AW

capacitors are rated in

Micro-farads & Volts AW

Which meter is used to bench check a motor for shorts or open

Ohmmeter AW

Which of the following meters must use internal power to check a load or circuit

Ohmmeter AW

Impedance is

Opposition to alternate current flow AW

An eletrical communated motor ECM is design to

Provide proper airflow under various conditions AW

Like Charges

Repel each other AW

A capacitor analyzer is designed to read

The capacitive resistance of a compacitor Aw

when checking the windings of a singlw phase motor

The common to run the terminals show the lowest resistence AW

When resistors are wired in parallel

The voltage drops across each resistor will be the same as the applied source of voltage AW

A three phase load requires a minimum of;

Three supply lines AW

On electric oil safety switch what changes the pressure signal to an electric signal

Tranducer

Tran-former are rated according to

VA at the secondary AW

which of the following is the correct formula for determining the wattage in a eletrical circuit

W=E times I AW

which of the following is the symbol for impedance in an AC circuit

Z AW

When current flow ina two wire circuit such as 120 volts if clamp on an amp meter is clamped around both wires. what measurement would be expected

Zero amps due to cancellation of the two feilds AW

In a series circuit, the voltage drop across each resistance will

add up to equal the source voltage AW

to change the direction of a three phase motor

change the position of any two supply wires AW

Contractors are rated according to the maximum amperage through the

contacts AW

a diode is used to

control the direction of electron flow AW

A____ is commonly used on a simgle phase capacitor starts fractional horsepower compressor motor to disconnect the start winding after the motor

current relay AW

direct didital control is

electronic controls used for equipmennt operation and monitoring AW

Which of the following would be considered an inductive load

eletrical motor AW

Capacitor are always connected_____ to the start winding

in series AW

when the temperatur of positive temperature coefficient thermistor increases its resistor will

increase AW

A device with overload protection used to control a motor is a

line starter AW

The thermal overload contacts on a line starter are usually __ reset.

manual AW

Single phase motor speed is determined by the

number of stator poles AW

in the schematic the voltage would be found across the cantact when energized in line #8

o volts AW

What would be the result if a 24 volt 20 ohm low voltage contractor coil were wired in series in with 24 volt 200 0hm control relay coil

only the control relay would operate AW

resistence

opposition to alternate current flow only AW

the____ drawing illistrates where the components are located in small appliances

pictorial AW

A transducer can create signal based on

pressure AW

Circuit breakers and fuses are primarily used to provide

protection from an overload of current AW

if contacta become badly pitted it is acceptable to

replace the contracts or control AW

One a good single compressor motor which winding terminals have the highest resistance

run to start AW

What is the term used to describe the output side of a tranformer

secondary side AW

Excessive current can be caused by

short circuit AW

Which of the following materials would best be suited for a semi conductor

silicone AW

When testing the windings of a single phase motors

the common to run terminals show the lowest resitence AW

Direction of rotation of a single phase induction motor is determined by

the direction of current flow through the start winding AW

In electrical wiring, a black colored wire in an alternating current circuit usually indicates?

the hot conductor AW

To discharge a capacitor prior to ohmmeter testing

use a 15000 or 20000 ohm 2 to 5 watt resistor AW

A step-up transformer increases

voltage AW

Fuses are sized by

volts and amps AW

the eletric meter on a house measures the____ passing through it

wattage AW