Question 1

A voltmeter is used to measure __________.

Accepted Answer

A voltmeter is used to measure voltage, not amperage (which is measured by an ammeter), resistance (which is measured by a megohmmeter), or continuity (which is tested using a continuity tester).

Question 2

One megohm is equal to __________ ohms.

Accepted Answer

The prefix "mega" means one million. Therefore, one megohm is equal to one million ohms.

Question 3

A voltage tester is considered to be a very accurate meter when compared to a voltmeter.

Accepted Answer

A voltage tester is a basic tool that can indicate the presence or absence of voltage in a circuit. It is not designed to measure precise voltage values and is therefore less accurate than a voltmeter, which is specifically designed for measuring voltage levels.

Question 4

Kilowatt-hour meters are used to measure __________.

Accepted Answer

Kilowatt-hour meters are designed to measure the amount of electrical energy consumed over a period of time, typically measured in hours. This is calculated by measuring the power being used, typically in kilowatts, and multiplying it by the length of time it's being used for, in hours. Therefore, the best choice would be B: electrical energy.

Question 5

An instrument used to measure values of resistance is called a(n) __________.

Accepted Answer

An ohmmeter is specifically designed to measure resistance. Ammeters measure current, voltmeters measure voltage, and wattmeters measure power.

Question 6

A meter that uses a moving pointer or needle to indicate a value on a scale is called a(n) __________ meter.

Accepted Answer

A moving pointer or needle is a characteristic of an analog meter. An LCD meter would use a digital display, while a digital meter would use numerical digits to display values. Parallax refers to an error in measurement caused by viewing a scale from an angle.

Question 7

A Wiggy is an electrical trade name for a __________.

Accepted Answer

A Wiggy is a solenoid type voltage tester commonly used by electricians to test for the presence of voltage in electrical circuits. It was named after its inventor, George Wigginton. It works by detecting the magnetic field around a live wire and giving an indication (usually a light or sound) if voltage is present.

Question 8

Electrical power is measured in __________.

Accepted Answer

Electrical power is measured in watts (W). While amps (A), ohms (Ω), and volts (V) are all important measurements in electricity, they are not measurements of power. Amps measures electrical current, ohms measures electrical resistance, and volts measures electrical potential difference.

Question 9

__________ are load types where the load impedance is not constant.

Accepted Answer

Non-linear loads, such as electronic devices and LED lighting, have a variable impedance that changes based on the voltage and current waveform, resulting in distortion and harmonics in the power system. Harmonics (A) are a type of distortion caused by non-linear loads, but they are not load types themselves. Linear loads (B) have a constant impedance and do not cause distortion or harmonics. True RMS (D) is a method for accurately measuring AC voltage and current regardless of waveform shape, but it is not related to load types.

Question 10

A break in an electrical conductor or cable is called a(n) __________ circuit.

Accepted Answer

An open circuit is a break in the electrical conductor or cable, which prevents the current from flowing through the circuit. A linear or non-linear circuit refers to the behavior of the circuit components with the applied voltage or current, while a short circuit is a connection between two conductors with very low resistance. Therefore, the best choice for this question is C - open circuit.

Question 11

A(n) __________ is used to determine the amount of resistance to the earth through a grounding electrode.

Accepted Answer

A ground resistance meter is specifically designed to measure the resistance to earth through a grounding electrode, and is therefore the best choice for this task. Multimeters can measure several electrical properties, but may not be as accurate or designed for measuring ground resistance. Meggers measure insulation resistance, not ground resistance. Wiggys are typically used for measuring AC voltage, and are not designed for measuring ground resistance.

Question 12

A voltage tester indicates only approximate voltage measurements.

Accepted Answer

Voltage testers do not provide precise voltage measurements and are only an approximate indicator of voltage presence. More accurate measurements require the use of a multimeter or other specialized measuring equipment.

Question 13

The letters VOM are an abbreviation for volt, ohm, and __________.

Accepted Answer

VOM is an abbreviation for Volt-Ohm-Milliammeter, indicating a device that measures voltage, resistance (in ohms), and current (in milliamps). Therefore, the correct choice is C, milliammeter.

Question 14

Which of the following test instruments must be used only when the circuit in not energized?

Accepted Answer

An ohmmeter must be used only when the circuit is not energized, as connecting it to an energized circuit can cause damage to the instrument and pose a safety hazard. Ammeters, voltmeters, and wattmeters can be used to measure current, voltage, and power in energized circuits.

Question 15

An analog ohmmeter scale is read from left to right.

Accepted Answer

It reads from the right to the left.

Question 16

__________ meters provide accurate measurements of AC values in environments where the basic AC waveform is distorted.

Accepted Answer

True RMS meters are designed to accurately measure AC values in environments where the basic AC waveform is distorted due to non-linear loads or other factors. They take into account the variations in waveform and provide an accurate measurement of the true root-mean-square value of the AC signal.

Question 17

A(n) __________ can indicate that voltage is present on a circuit without actually being connected to the circuit.

Accepted Answer

A non-contact voltage tester can detect voltage without physical contact with a circuit, making it a safe and convenient tool for electrical work.

Question 18

Never work on energized electrical equipment unless it is absolutely necessary.

Accepted Answer

Working on energized electrical equipment puts you at risk of electrical shock and other injuries. It is always safer to de-energize the equipment before working on it, whenever possible.

Question 19

When using measuring instruments, be sure to use an instrument that has a rating less than the highest value of electricity that you expect to be measuring.

Accepted Answer

Using an instrument with a rating less than the highest value of electricity expected to be measured can be dangerous and may damage the instrument. It's important to use an instrument that can safely and accurately measure the highest expected value.

Question 20

__________ are frequencies that are multiples of the fundamental 60 Hertz frequency.

Accepted Answer

Harmonics are frequencies that are integer multiples of the fundamental frequency. In this case, the fundamental frequency is 60 Hz, and harmonics would include 120 Hz, 180 Hz, 240 Hz, etc. Linear loads and non-linear loads refer to the types of loads that are connected to the power source, while True RMS is a method of measuring AC voltage or current.

Quiz 4: Test and Measurement Instruments Used in Residential Wiring