Explore topic-wise MCQs in Electronics.

This section includes 99 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.

51.

If a variable resistor's resistance varies in a nonuniform manner as the shaft is moved, it is considered to be:

A. linear
B. defective
C. not wirewound
D. tapered
Answer» E.
52.

How is power dissipated in a resistor?

A. by resistance
B. by voltage
C. by current
D. by heat
Answer» E.
53.

The six basic forms of energy are:

A. light, sun, magnetic, chemical, electrical, and mechanical
B. electrical, mechanical, light, heat, magnetic, and chemical
C. electrical, mechanical, sun, heat, chemical, and light
D. potential, sun, light, chemical, electrical, and mechanical
Answer» C. electrical, mechanical, sun, heat, chemical, and light
54.

If resistance decreases, then current will:

A. decrease
B. increase
C. remain the same
D. double
Answer» C. remain the same
55.

The source is 24 volts and the load resistance is 100 . What is the load current?

A. 2.4 A
B. 240 mA
C. 24 mA
D. 2.4 mA
Answer» C. 24 mA
56.

Resistance is:

A. the opposition to current flow accompanied by the dissipation of heat
B. symbolized by R, measured in ohms, and directly proportional to conductance
C. directly proportional to current and voltage
D. represented by the flow of fluid in the fluid circuit
Answer» B. symbolized by R, measured in ohms, and directly proportional to conductance
57.

Carbon composition resistors are the most common and the least expensive type of fixed-value resistor.

A. 1
B.
Answer» B.
58.

Good insulators:

A. have few electrons in their outer shells
B. have a large dielectric strength
C. have a small breakdown voltage
D. have many electrons in the nucleus
Answer» C. have a small breakdown voltage
59.

What are the two major categories for resistors?

A. low and high ohmic value
B. commercial and industrial
C. low and high power value
D. fixed and variable
Answer» E.
60.

With Ohm's law:

A. current is inversely proportional to resistance
B. resistance is directly proportional to voltage
C. voltage is indirectly proportional to power
D. current is directly proportional to resistance
Answer» B. resistance is directly proportional to voltage
61.

Resistance limits the flow of current.

A. 1
B.
Answer» B.
62.

Ohm's law is not:

A. V = IR
B. I = V/R
C. R = IV
D. R = V/I
Answer» D. R = V/I
63.

A 33 k resistor with a 20% tolerance checks out as ok with which of the following ohmmeter readings?

A. 26400 ohms
B. 24183 ohms
C. 6600 ohms
D. 39970 ohms
Answer» B. 24183 ohms
64.

How many connections does a potentiometer have?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
65.

4 amperes will flow through a 10 resistor if 20 volts are placed across the resistor.

A. 1
B.
Answer» C.
66.

The word work means that:

A. energy has been transferred
B. it is inversely related to energy
C. no energy has been transferred
D. work and energy are not related
Answer» B. it is inversely related to energy
67.

Power is measured in units of:

A. joules x charge
B. joules/work
C. joules x voltage
D. joules/time
Answer» E.
68.

Resistance in a circuit is:

A. opposition to current
B. opposition to voltage
C. the same as current
D. the same as voltage
Answer» B. opposition to voltage
69.

If a calculator display was "0.00263," what would this answer be in percent?

A. 0.0003
B. 0.0026
C. 0.0263
D. 0.263
Answer» C. 0.0263
70.

A good fuse will have:

A. zero ohms resistance
B. a medium resistance
C. a high resistance
D. an infinite resistance
Answer» B. a medium resistance
71.

Electrical equipment is protected against excessive current by a(n):

A. fusible wire link
B. insulated glass container
C. metal ended coil
D. circuit opener
Answer» B. insulated glass container
72.

If 500 mA is flowing through a 10 resistor, the wattage rating of the resistor should be 2 watts.

A. 1
B.
Answer» C.
73.

Resistors are identified as to wattage by:

A. size
B. color code
C. types of materials
D. internal construction
Answer» B. color code
74.

A digital voltmeter can be used to measure resistance.

A. 1
B.
Answer» B.
75.

The unit designator for resistance value is the:

A. ampere
B. ohm
C. volt
D. watt
Answer» C. volt
76.

Wirewound resistors are usually used in circuits that have:

A. high current
B. negative temperature coefficients
C. low power
D. high voltage
Answer» B. negative temperature coefficients
77.

Resistor tolerance is either printed on the component, or is provided by:

A. keyed containers
B. size
C. color code
D. ohmmeter reading
Answer» D. ohmmeter reading
78.

A potentiometer has how many leads?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
79.

An ohmmeter uses an internal battery to measure the resistance of a resistor.

A. 1
B.
C. 1
D.
Answer» B.
80.

For P = V2/R, a decrease in resistance should produce:

A. a decrease in power
B. an increase in ohms
C. an increase in power
D. a decrease in current
Answer» D. a decrease in current
81.

After a lamp is turned on, its filament resistance will change to become:

A. less resistive
B. cooler
C. brighter
D. more resistive
Answer» E.
82.

One problem with mechanically variable resistors is noticeable in audio circuits as:

A. scratchy noise
B. lack of bass response
C. variable volume
D. too much treble response
Answer» B. lack of bass response
83.

Which type of test equipment is used to measure resistors?

A. ohmmeter
B. ammeter
C. voltmeter
D. watt meter
Answer» B. ammeter
84.

A rheostat is ___.

A. a two-terminal device that controls current
B. a three-terminal device that controls current
C. a two-terminal device that divides voltage
D. a three-terminal device that divides voltage
Answer» B. a three-terminal device that controls current
85.

If a metallic conductor has a positive temperature coefficient of resistance, then:

A. as temperature increases, resistance decreases
B. as current increases, resistance decreases
C. as voltage increases, current increases
D. as temperature increases, resistance increases
Answer» E.
86.

What is the most commonly used conductor in electronics?

A. aluminum
B. copper
C. gold
D. silver
Answer» C. gold
87.

How many connections does a rheostat have?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
88.

With Ohm's law, if voltage increases and resistance stays the same:

A. current remains the same
B. power decreases
C. current increases
D. resistance decreases
Answer» D. resistance decreases
89.

A 22-gauge wire will have a diameter in mils of:

A. 10.03
B. 22.35
C. 45.26
D. 71.96
Answer» C. 45.26
90.

What current is flowing in the circuit?

A. 288 kA
B. 2 kA
C. 50 mA
D. 500 A
Answer» E.
91.

With 1 mA of current, what wattage rating should a 470 ohm resistor have?

A. 1/4 watt
B. 1/2 watt
C. 1 watt
D. 2 watts
Answer» B. 1/2 watt
92.

A 12-volt battery is delivering 3 amperes to a resistor. The power dissipated by the resistor is 4 watts.

A. 1
B.
C. 1
D.
Answer» C. 1
93.

How many amps are used by a 100 watt, 120 volt light bulb?

A. 1.2 amps
B. 12000 amps
C. 830 mA
D. 12 amps
Answer» D. 12 amps
94.

One ampere of current flowing through one ohm of resistance is equal to:

A. 1 horsepower
B. 1 Btu
C. 1 watt
D. 1 joule
Answer» D. 1 joule
95.

How is a 3.9 k resistor color-coded?

A. red, white, red, gold
B. red, green, orange, silver
C. orange, white, red, gold
D. orange, green, orange, silver
Answer» D. orange, green, orange, silver
96.

How do fixed resistors usually fail?

A. slowly over time
B. by increasing their value
C. by becoming an open circuit
D. by increasing their value and becoming an open circuit
Answer» D. by increasing their value and becoming an open circuit
97.

Which formula shows a direct proportionality between power and voltage?

A. V = IR
B. P = VI
C. P = IR
D. I = V/R
Answer» C. P = IR
98.

How many basic types of resistors exist?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
99.

The resistivity of copper is:

A. 9.9
B. 10.7
C. 16.7
D. 17
Answer» C. 16.7