CETA CERTIFICATION MASTERY:
200 PRACTICE MCQS +
RATIONALES | ETA ELECTRONICS
TECHNICIAN EXAM PREP 2025
Question 1
What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Resistance opposes current flow and is measured in ohms (Ω), named
after Georg Ohm. Volts measure potential difference; amperes measure
current; watts measure power.
Answer: C
Question 2
According to Ohm's Law, what is the current through a 100 Ω resistor
with 12 V applied?
A) 0.12 A
B) 8.33 A
C) 1200 A
D) 1.2 A
Ohm's Law: I = V/R = 12 V / 100 Ω = 0.12 A (or 120 mA). Always ensure
units are consistent before calculating.
Answer: A
Question 3
,Which component stores energy in an electric field?
A) Resistor
B) Inductor
C) Capacitor
D) Diode
Capacitors store energy in an electric field between two conductive plates
separated by a dielectric. Inductors store energy in a magnetic field;
resistors dissipate energy as heat; diodes allow current flow in one
direction.
Answer: C
Question 4
In a series circuit, what happens to total resistance when more resistors
are added?
A) Decreases
B) Increases
C) Stays the same
D) Becomes zero
In series circuits, total resistance is the sum of individual resistances: Rₜ
= R₁ + R₂ + R₃... Adding resistors always increases total resistance.
Answer: B
Question 5
What is the frequency of standard household AC power in the United
States?
A) 50 Hz
B) 60 Hz
C) 120 Hz
D) 240 Hz
North American utility power operates at 60 Hz (cycles per second).
Many other countries use 50 Hz. Frequency affects transformer design
and motor operation.
,Answer: B
Question 6
Which instrument is used to measure voltage in a circuit?
A) Ammeter
B) Ohmmeter
C) Voltmeter
D) Wattmeter
A voltmeter measures potential difference (voltage) and is connected in
parallel across the component. Ammeters measure current (series
connection); ohmmeters measure resistance (power off).
Answer: C
Question 7
What type of current flows in only one direction?
A) Alternating Current (AC)
B) Direct Current (DC)
C) Pulsating Current
D) Reactive Current
Direct Current (DC) flows consistently in one direction, as from batteries
or DC power supplies. Alternating Current (AC) reverses direction
periodically.
Answer: B
Question 8
In a parallel circuit with two 100 Ω resistors, what is the total resistance?
A) 200 Ω
B) 100 Ω
C) 50 Ω
D) 25 Ω
, For parallel resistors: 1/Rₜ = 1/R₁ + 1/R₂ = 1/100 + 1/100 = 2/100 → Rₜ
= 50 Ω. Parallel circuits always have total resistance less than the
smallest branch.
Answer: C
Question 9
Which semiconductor device allows current to flow in only one
direction?
A) Transistor
B) Capacitor
C) Diode
D) Inductor
A diode is a two-terminal semiconductor that conducts current primarily
in one direction (forward bias) and blocks it in reverse bias. Used for
rectification, protection, and signal demodulation.
Answer: C
Question 10
What is the power dissipated by a 10 Ω resistor with 5 A flowing through
it?
A) 2.5 W
B) 50 W
C) 250 W
D) 500 W
Power formula: P = I²R = (5 A)² × 10 Ω = 25 × 10 = 250 W.
Alternatively: V = IR = 50 V, then P = VI = 50 × 5 = 250 W.
Answer: C
Question 11
Which color code represents a 1 kΩ resistor with ±5% tolerance?
A) Brown-Black-Red-Gold
B) Brown-Black-Orange-Gold
C) Red-Black-Red-Silver
200 PRACTICE MCQS +
RATIONALES | ETA ELECTRONICS
TECHNICIAN EXAM PREP 2025
Question 1
What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Resistance opposes current flow and is measured in ohms (Ω), named
after Georg Ohm. Volts measure potential difference; amperes measure
current; watts measure power.
Answer: C
Question 2
According to Ohm's Law, what is the current through a 100 Ω resistor
with 12 V applied?
A) 0.12 A
B) 8.33 A
C) 1200 A
D) 1.2 A
Ohm's Law: I = V/R = 12 V / 100 Ω = 0.12 A (or 120 mA). Always ensure
units are consistent before calculating.
Answer: A
Question 3
,Which component stores energy in an electric field?
A) Resistor
B) Inductor
C) Capacitor
D) Diode
Capacitors store energy in an electric field between two conductive plates
separated by a dielectric. Inductors store energy in a magnetic field;
resistors dissipate energy as heat; diodes allow current flow in one
direction.
Answer: C
Question 4
In a series circuit, what happens to total resistance when more resistors
are added?
A) Decreases
B) Increases
C) Stays the same
D) Becomes zero
In series circuits, total resistance is the sum of individual resistances: Rₜ
= R₁ + R₂ + R₃... Adding resistors always increases total resistance.
Answer: B
Question 5
What is the frequency of standard household AC power in the United
States?
A) 50 Hz
B) 60 Hz
C) 120 Hz
D) 240 Hz
North American utility power operates at 60 Hz (cycles per second).
Many other countries use 50 Hz. Frequency affects transformer design
and motor operation.
,Answer: B
Question 6
Which instrument is used to measure voltage in a circuit?
A) Ammeter
B) Ohmmeter
C) Voltmeter
D) Wattmeter
A voltmeter measures potential difference (voltage) and is connected in
parallel across the component. Ammeters measure current (series
connection); ohmmeters measure resistance (power off).
Answer: C
Question 7
What type of current flows in only one direction?
A) Alternating Current (AC)
B) Direct Current (DC)
C) Pulsating Current
D) Reactive Current
Direct Current (DC) flows consistently in one direction, as from batteries
or DC power supplies. Alternating Current (AC) reverses direction
periodically.
Answer: B
Question 8
In a parallel circuit with two 100 Ω resistors, what is the total resistance?
A) 200 Ω
B) 100 Ω
C) 50 Ω
D) 25 Ω
, For parallel resistors: 1/Rₜ = 1/R₁ + 1/R₂ = 1/100 + 1/100 = 2/100 → Rₜ
= 50 Ω. Parallel circuits always have total resistance less than the
smallest branch.
Answer: C
Question 9
Which semiconductor device allows current to flow in only one
direction?
A) Transistor
B) Capacitor
C) Diode
D) Inductor
A diode is a two-terminal semiconductor that conducts current primarily
in one direction (forward bias) and blocks it in reverse bias. Used for
rectification, protection, and signal demodulation.
Answer: C
Question 10
What is the power dissipated by a 10 Ω resistor with 5 A flowing through
it?
A) 2.5 W
B) 50 W
C) 250 W
D) 500 W
Power formula: P = I²R = (5 A)² × 10 Ω = 25 × 10 = 250 W.
Alternatively: V = IR = 50 V, then P = VI = 50 × 5 = 250 W.
Answer: C
Question 11
Which color code represents a 1 kΩ resistor with ±5% tolerance?
A) Brown-Black-Red-Gold
B) Brown-Black-Orange-Gold
C) Red-Black-Red-Silver
