Chapter 8 - Analog and Digital Multimeters - Grob's Basic Electronics 13th

For a moving-coil meter movement, IM is: a. the amount of current needed in the moving coil to produce full-scale deflection of the meter's pointer. b. the value of current flowing in the moving coil for any amount of pointer deflection. c. the amount of current required in the moving coil to produce half-scale deflection of the meter's pointer. d. none of the above.

a

For an analog VOM with a mirror along the printed scale: a. the pointer deflection will be magnified by the mirror when measuring small values of voltage, current, and resistance. b. the meter should always be read by looking at the meter from the side. c. the meter is read when the pointer and its mirror reflection appear as one. d. both a and b.

c

A current meter should have a: a. very high internal resistance. b. very low internal resistance. c. infinitely high internal resistance. d. none of the above.

b

A voltmeter should have a: a. resistance of about 0 Ω. b. very low resistance. c. very high internal resistance. d. none of the above.

c

Voltmeter loading is usually a problem when measuring voltages in: a. parallel circuits. b. low-resistance circuits. c. a series circuit with low-resistance values. d. high-resistance circuits.

d

To double the current range of a 50-µA, 2-kΩ moving-coil meter movement, the shunt resistance, RS, should be: a. 2 kΩ. b. 1 kΩ. c. 18 kΩ. d. 50 kΩ.

a

A voltmeter using a 20-µA meter movement has an Ω/V rating of: a. 20 kΩ/V. b. 50 kΩ/V. c. 1 kΩ/V. d. 10 MΩ/V.

b

As the current range of an analog meter is increased, the overall meter resistance, RM, a. decreases. b. increases. c. stays the same. d. none of the above.

a

As the voltage range of an analog VOM is increased, the total voltmeter resistance, RV, a. decreases. b. increases. c. stays the same. d. none of the above.

b

An analog VOM has an Ω/V rating of 10 kΩ/V. What is the voltmeter resistance, RV, if the voltmeter is set to the 25-V range? a. 10 kΩ. b. 10 MΩ. c. 25 kΩ. d. 250 kΩ.

d

What shunt resistance, RS, is needed to make a 100-µA, 1-kΩ meter movement capable of measuring currents from 0 to 5 mA? a. 25 Ω. b. 10.2 Ω. c. 20.41 Ω. d. 1 kΩ.

c

For a 30-V range, a 50-µA, 2-kΩ meter movement needs a multiplier resistor of: a. 58 kΩ. b. 598 kΩ. c. 10 MΩ. d. 600 kΩ.

b

When set to any of the voltage ranges, a typical DMM has an input resistance of: a. about 0 Ω. b. 20 kΩ. c. 10 MΩ. d. 1 kΩ.

c

When using an ohmmeter to measure resistance in a circuit: a. the power in the circuit being tested must be off. b. the power in the circuit being tested must be on. c. the power in the circuit being tested may be on or off. d. the power in the circuit being tested should be turned on after the leads are connected.

a

Which of the following voltages cannot be displayed by a DMM with a 3½-digit display? a. 7.64 V. b. 13.5 V. c. 19.98 V. d. 29.98 V.

d

What type of meter can be used to measure AC currents without breaking open the circuit? a. An analog VOM. b. An amp-clamp probe. c. A DMM. d. There isn't such a meter.

b

Which of the following measurements is usually the most inconvenient and time-consuming when troubleshooting? a. resistance measurements. b. DC voltage measurements. c. current measurements. d. AC voltage measurements.

c

An analog ohmmeter reads 18 on the R × 10 k range. What is the value of the measured resistance? a. 180 kΩ. b. 18 kΩ. c. 18 Ω. d. 180 Ω.

a

Which meter has a higher resistance, a DMM with 10 MΩ of resistance on all DC voltage ranges or an analog VOM with a 50 kΩ/V rating set to the 250-V range? a. the DMM. b. the analog VOM. c. They both have the same resistance. d. It cannot be determined.

b

When using an ohmmeter to measure the continuity of a wire, the resistance should measure: a. about 0 Ω if the wire is good. b. infinity if the wire is broken (open). c. very high resistance if the wire is good. d. both a and b.

d