Question 1

Many digital meters have voltage range settings from 20 millivolts to 200 volts, and the higher ranges are used for accuracy.

Accepted Answer

Digital meters have voltage range settings to accommodate different levels of voltage, but using a higher range does not necessarily increase accuracy. Accuracy depends on the meter's resolution and precision, not just the range setting. Higher ranges are used to measure higher voltages safely without damaging the meter.

Question 2

To use an ohmmeter, the tips of the test leads are first held together (short circuited) and the rheostat (variable resistor) is adjusted so that the meter pointer moves to the ____ of the scale and points to the 0 ohms mark.
A)left-hand end
B)middle
C)right-hand end
D)bottom

Accepted Answer

When the test leads are short-circuited, the resistance is zero, so the pointer should move to the right-hand end of the scale, which is marked as 0 ohms.

Question 3

A simple galvanometer, by itself, has a very limited use; the most useful galvanometers are scaled as macroammeters.

Accepted Answer

A simple galvanometer is primarily used to detect and measure electric current, not scaled as macroammeters. For measuring larger currents, a galvanometer can be converted into an ammeter by connecting it in parallel with a low resistance (shunt), not by scaling it as a macroammeter.

Question 4

A ____ has a tapered jaw that can be opened and closed single-handedly by pressure action on a side lever.
A)clamp-on accessory
B)meter reader
C)connecting reader
D)clamp meter

Accepted Answer

The description matches that of a clamp meter, which has a tapered jaw that can be opened and closed single-handedly by pressure action on a side lever. A clamp-on accessory is a general term and does not necessarily have a tapered jaw or a side lever. Meter reader and connecting reader are not relevant to the given description.

Question 5

Meter manufacturers generally make meter shunts of a material called manganin (a copper-nickel-manganese alloy) rather than copper.

Accepted Answer

This is because manganin has a low temperature coefficient of resistivity, which means that its resistance does not change much with temperature, making it more accurate for use in measuring current. Copper, on the other hand, has a higher temperature coefficient of resistivity and is more prone to heat-induced changes in resistance.

Question 6

To measure the wattage of a circuit, a meter must have two coils; one coil is affected by the magnetism and one by the resistance.

Accepted Answer

Wattage in a circuit is measured by calculating the product of voltage and current. A wattmeter, which measures wattage, typically has two coils: a current coil and a voltage coil, not coils for magnetism and resistance.

Question 7

A voltmeter is obtained by connecting a high resistance in series with the galvanometer, and these voltage-dropping, series-connected resistors are known as ____.
A)Aryton shunts
B)additions
C)multipliers
D)droppers

Accepted Answer

The resistors used in series with a galvanometer to create a voltmeter are known as multipliers because they multiply the voltage being measured to a higher value that can be read on the galvanometer scale. Aryton shunts are used in parallel with the galvanometer to create an ammeter, additions and droppers are not common terms used in relation to voltmeters.

Question 8

Most digital meters have an input impedance of about ____ megohms on all ranges.
A)10
B)30
C)35
D)50

Accepted Answer

Most digital meters are designed with an input impedance of about 10 megohms across all ranges to minimize their impact on the circuit being measured.

Question 9

To measure large currents with the galvanometer, a known large fraction of a large current is bypassed through a parallel low resistor called a ____.
A)tunnel
B)shoot
C)connection cable
D)shunt

Accepted Answer

The shunt resistor is a low resistance element connected in parallel with the galvanometer, to divert most of the current being measured so that only a fraction of it passes through the galvanometer. This allows the galvanometer to measure large currents accurately.

Question 10

Ammeters, voltmeters, and ohmmeters are all similar in construction and are modifications of a basic instrument called a(n) ____.
A)galvanometer
B)magnetometer
C)polarized meter
D)analog meter

Accepted Answer

Ammeters, voltmeters, and ohmmeters are all modifications of a basic instrument called a galvanometer.

Question 11

Digital ohmmeters measure resistance by measuring the amount of voltage drop across an unknown resistance.

Accepted Answer

Digital ohmmeters measure resistance by applying a known voltage and then measuring the resulting current or voltage drop across the unknown resistance using Ohm's law. They convert the voltage or current reading into resistance using internal circuitry.

Question 12

Analog meters change scale value by inserting or removing ____ from the meter circuit.
A)volts
B)amps
C)resistance
D)power

Accepted Answer

Analog meters use a fixed level of current to measure resistance, so changing the amount of resistance in the circuit will change the scale value.

Question 13

The ____ contains a high-voltage generator that supplies current through the series resistors and the unknown resistance (R) to the two-coil assembly that operates the pointer.
A)megohmmeter
B)macrohmmeter
C)millohmmeter
D)kilohmmeter

Accepted Answer

Megohmmeter is a device used to measure very high resistances in the megaohm range. It typically uses a high voltage generator to supply current through the unknown resistance and measure the resulting voltage. The other options (macrohmmeter, millohmmeter, kilohmmeter) are not typically associated with high voltage resistance measurements.

Question 14

The quality of a voltmeter is indicated by its conductivity, that is to say, by the amount of current required to force the pointer to the end of the scale (full-scale deflection.).

Accepted Answer

The quality of a voltmeter is actually indicated by its accuracy and precision, not by its conductivity. The amount of current required for full-scale deflection is not relevant to the quality.

Question 15

Wattmeters that contain both stationary and moving coils are generally referred to as ____ wattmeters.
A)stable
B)dynamic
C)flexible
D)variable

Accepted Answer

Wattmeters that contain both stationary and moving coils are commonly referred to as dynamic wattmeters. The moving coil is suspended within a magnetic field generated by the stationary coils, creating a torque that causes the coil to move. This movement is proportional to the power being measured, allowing for accurate power measurement.

Question 16

A(n) ____ measures voltage, but it does not contain a meter movement or digital display.
A)voltage tester
B)ohm-tester
C)voltage meter
D)ohmmeter

Accepted Answer

A voltage tester is used to measure voltage, but it does not have a meter movement or digital display. Instead, it usually has LEDs or audible signals to indicate the voltage level. Ohm-testers and ohmmeters measure resistance, while a voltage meter typically has a meter movement or digital display to show the voltage level.

Question 17

An ohmmeter must never be connected to a circuit when the power is turned on.

Accepted Answer

Connecting an ohmmeter to a live circuit can cause the meter to short out and potentially damage the circuit or injure the person handling the meter. Always ensure the power is turned off before using an ohmmeter.

Question 18

One of the most common methods used to accurately measure values of resistance, inductance, and capacitance is with a bridge constructed by connecting four components together to form a parallel-series circuit.

Accepted Answer

This statement is true. A bridge circuit is commonly used to measure values of resistance, inductance, and capacitance by comparing them to known values in a balanced circuit. The bridge circuit typically consists of four components arranged in a parallel-series configuration.

Question 19

To measure very low resistance values, a volt-ohmmeter is used.

Accepted Answer

To measure very low resistance values, a method called the four-wire (4-wire) Kelvin method or a micro-ohmmeter is typically used, not a standard volt-ohmmeter, to avoid inaccuracies due to lead and contact resistances.

Question 20

Instruments used for measuring electrical quantities are generally classified as analog or digital meters.

Accepted Answer

This statement is true. Electrical measuring instruments can be classified as either analog or digital meters.

Quiz 17: Electrical Measuring Instruments Another Application of Electromagnetism

Many digital meters have voltage range settings from 20 millivolts to 200 volts, and the higher ranges are used for accuracy.

To use an ohmmeter, the tips of the test leads are first held together (short circuited) and the rheostat (variable resistor) is adjusted so that the meter pointer moves to the ____ of the scale and points to the 0 ohms mark.

A simple galvanometer, by itself, has a very limited use; the most useful galvanometers are scaled as macroammeters.

A ____ has a tapered jaw that can be opened and closed single-handedly by pressure action on a side lever.

Meter manufacturers generally make meter shunts of a material called manganin (a copper-nickel-manganese alloy) rather than copper.

To measure the wattage of a circuit, a meter must have two coils; one coil is affected by the magnetism and one by the resistance.

A voltmeter is obtained by connecting a high resistance in series with the galvanometer, and these voltage-dropping, series-connected resistors are known as ____.

Most digital meters have an input impedance of about ____ megohms on all ranges.

To measure large currents with the galvanometer, a known large fraction of a large current is bypassed through a parallel low resistor called a ____.

Ammeters, voltmeters, and ohmmeters are all similar in construction and are modifications of a basic instrument called a(n) ____.

Digital ohmmeters measure resistance by measuring the amount of voltage drop across an unknown resistance.

Analog meters change scale value by inserting or removing ____ from the meter circuit.

The ____ contains a high-voltage generator that supplies current through the series resistors and the unknown resistance (R) to the two-coil assembly that operates the pointer.

The quality of a voltmeter is indicated by its conductivity, that is to say, by the amount of current required to force the pointer to the end of the scale (full-scale deflection.).

Wattmeters that contain both stationary and moving coils are generally referred to as ____ wattmeters.

A(n) ____ measures voltage, but it does not contain a meter movement or digital display.

An ohmmeter must never be connected to a circuit when the power is turned on.

One of the most common methods used to accurately measure values of resistance, inductance, and capacitance is with a bridge constructed by connecting four components together to form a parallel-series circuit.

To measure very low resistance values, a volt-ohmmeter is used.

Instruments used for measuring electrical quantities are generally classified as analog or digital meters.