CETa Associate Level Certification — Questions and Answers

Question 1: What is the purpose of a 'revision history' block in technical documentation?

To track changes made to the document over time, including dates, descriptions, and author of each revision (Correct answer)
To list all engineers who reviewed the document for legal liability
To document approval signatures required before implementation
To specify the software version used to create the document

Correct answer: To track changes made to the document over time, including dates, descriptions, and author of each revision

A revision history block records all document changes chronologically, including revision number, date, description of change, and who made it, ensuring traceability.

Question 2: A multiplexer (MUX) with 4 select lines can route how many input channels?

4
16 (Correct answer)
8
32

Correct answer: 16

A MUX with n select lines supports 2ⁿ inputs; 4 select lines → 2⁴ = 16 input channels.

Question 3: A transformer has 500 primary turns and 50 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?

6 V
1200 V
12 V (Correct answer)
120 V

Correct answer: 12 V

Turns ratio Ns/Np = Vs/Vp → Vs = 120 × (50/500) = 12 V; this is a 10:1 step-down transformer.

Question 4: In a series RLC circuit, what is the condition known as resonance?

The inductive reactance is greater than the capacitive reactance.
The capacitive reactance is greater than the inductive reactance.
The total impedance is equal to the resistance. (Correct answer)
The phase angle between voltage and current is 90 degrees.

Correct answer: The total impedance is equal to the resistance.

Resonance in a series RLC circuit occurs at the specific frequency where the inductive reactance (XL) equals the capacitive reactance (XC). When XL = XC, they cancel each other out in the impedance formula Z = √(R² + (XL - XC)²). This simplifies the impedance to Z = √R², meaning the total impedance (Z) is equal to the resistance (R), and the circuit behaves as purely resistive. At this point, the current in the circuit reaches its maximum value.

Question 5: The power factor of an AC circuit is defined as:

True power divided by apparent power (Correct answer)
True power divided by reactive power
Reactive power divided by apparent power
Apparent power divided by true power

Correct answer: True power divided by apparent power

Power factor equals true (real) power divided by apparent power, or equivalently cos(θ).

Question 6: On a dual-trace oscilloscope in CHOP mode versus ALT mode, CHOP mode is preferred when:

Displaying slow signals where ALT mode would cause visible flicker (Correct answer)
Both channels contain fast transient events
Measuring phase difference between two identical frequencies
Displaying very high frequency signals above 10 MHz

Correct answer: Displaying slow signals where ALT mode would cause visible flicker

CHOP mode rapidly switches between channels many times per sweep, giving smooth display of both traces at low sweep speeds where ALT mode would show annoying flicker.

Question 7: An electrolytic capacitor is installed with reversed polarity in a DC circuit. What will most likely occur?

It will act as a resistor
It may overheat and fail catastrophically (Correct answer)
It will work normally but with reduced capacitance
It will simply block current flow

Correct answer: It may overheat and fail catastrophically

Electrolytic capacitors are polarized; reverse polarity breaks down the oxide dielectric layer, causing excessive leakage current, heat, and possible explosion.

Question 8: What does a caution symbol on technical documentation indicate?

Product is waterproof
Potential hazard requiring attention (Correct answer)
Recyclable material
High-quality product

Correct answer: Potential hazard requiring attention

A caution symbol on technical documentation or equipment indicates a potential hazard that, if not avoided, could result in minor or moderate injury, or property damage. It serves as a warning to users to be aware of specific risks and to take necessary precautions. This is distinct from "warning" (serious injury/death) or "danger" (immediate, severe hazard).

Question 9: A technician is troubleshooting a digital logic circuit and finds that the output of a specific IC is always LOW, regardless of the inputs. The VCC and GND pins are confirmed to have the correct voltage. Which of the following is the most likely fault?

An open circuit on one of the logic inputs.
The subsequent IC in the signal path has a shorted input.
The system clock frequency is too high.
The output of the IC is internally shorted to ground. (Correct answer)

Correct answer: The output of the IC is internally shorted to ground.

If the output of an IC is permanently stuck in a LOW state (stuck-at-0 fault) even when the inputs should produce a HIGH output, and power connections are correct, it strongly indicates an internal failure. A common internal failure mode is for the output driver transistor to be shorted to the ground plane.

Question 10: In a J-K flip-flop, what is the output behavior when both J and K inputs are held HIGH (logic 1) and a clock pulse is applied?

The output is set to 1 (HIGH).
The output toggles to the opposite state. (Correct answer)
The output remains in its previous state.
The output is reset to 0 (LOW).

Correct answer: The output toggles to the opposite state.

When both J and K inputs of a J-K flip-flop are held HIGH, the flip-flop is in the 'toggle' mode. On each active clock edge, the output Q will invert to the opposite of its current state.

Question 11: Which BCD encoding assigns weights 8-4-2-1 to the four bit positions?

Natural BCD (8421) (Correct answer)
2-out-of-5 code
Excess-3
Gray code

Correct answer: Natural BCD (8421)

Natural BCD (8421) assigns positional weights 8, 4, 2, 1 from MSB to LSB, directly representing decimal digits 0–9.

Question 12: If the frequency of an AC signal doubles, what happens to the capacitive reactance (XC)?

XC remains the same
XC doubles
XC quadruples
XC halves (Correct answer)

Correct answer: XC halves

Since XC = 1/(2πfC), doubling frequency halves the capacitive reactance.

Question 13: What happens to total resistance when additional resistors are added in parallel to a circuit?

Total resistance stays the same
Total resistance increases
Total resistance decreases (Correct answer)
Total resistance doubles

Correct answer: Total resistance decreases

Adding parallel paths provides more routes for current flow, which always decreases total equivalent resistance.

Question 14: In a series-parallel circuit, two 10Ω resistors are in parallel and that combination is in series with a 5Ω resistor. What is the total resistance?

10Ω (Correct answer)
5Ω
15Ω
25Ω

Correct answer: 10Ω

Two 10Ω in parallel = 5Ω; 5Ω + 5Ω in series = 10Ω total.

Question 15: A 100Ω resistor dissipates 4W of power. What current flows through it?

0.2A (Correct answer)
2A
400A
0.04A

Correct answer: 0.2A

Using P = I²R, I = √(P/R) = √(4/100) = √0.04 = 0.2A.

Question 16: The knee voltage of a diode's I-V characteristic represents:

The maximum allowable forward current
The voltage at which forward current increases rapidly (Correct answer)
The peak inverse voltage rating
The reverse breakdown voltage

Correct answer: The voltage at which forward current increases rapidly

The knee voltage (approximately 0.7 V for silicon) is the forward bias point where the diode transitions from high to very low resistance and current increases sharply.

Question 17: What is the primary purpose of improving the power factor in an AC circuit, ideally towards unity (1.0)?

To reduce the total current drawn from the source for the same amount of real power. (Correct answer)
To maximize the phase angle between voltage and current.
To decrease the apparent power consumed by the load.
To increase the circuit's resonant frequency.

Correct answer: To reduce the total current drawn from the source for the same amount of real power.

Power factor is the ratio of real power (used to do work) to apparent power (total power supplied). A low power factor indicates that a significant portion of the current is not performing useful work. By improving the power factor towards unity (1.0), the apparent power becomes nearly equal to the real power. This means less total current is required from the source to deliver the same amount of real power, which reduces energy losses in the distribution system and allows for more efficient operation.

Question 18: What is the primary advantage of using a Darlington transistor pair configuration?

Very high current gain (β_total ≈ β₁ × β₂) with improved drive capability (Correct answer)
Faster switching speed than a single transistor
Lower saturation voltage than a single BJT
Lower forward voltage drop than a single BJT

Correct answer: Very high current gain (β_total ≈ β₁ × β₂) with improved drive capability

A Darlington pair multiplies the individual transistor beta values (β_total ≈ β₁ × β₂), providing very high current gain ideal for driving heavy loads from small input currents.

Question 19: Impedance matching between a source and load in an AC system is important primarily to:

Increase the resonant frequency
Minimize current flow
Reduce capacitive reactance
Maximize power transfer from source to load (Correct answer)

Correct answer: Maximize power transfer from source to load

Maximum power is transferred when the load impedance equals the complex conjugate of the source impedance.

Question 20: An open circuit condition in a series circuit causes:

Voltage source to short out
Maximum current through remaining components
Equal voltage across all components
Zero current through the entire circuit (Correct answer)

Correct answer: Zero current through the entire circuit

An open break in a series circuit stops all current flow since there is no complete path for current.

Question 21: A current of 3A flows through a 4Ω resistor for 10 seconds. How much energy is dissipated?

120 J
360 J (Correct answer)
36 J
1200 J

Correct answer: 360 J

Energy W = P × t = I²Rt = 3² × 4 × 10 = 9 × 4 × 10 = 360 J.

Question 22: Maximum power transfer from a source to a load occurs when load resistance equals:

The source's internal (Thevenin) resistance (Correct answer)
Infinite resistance
Zero ohms
Twice the source resistance

Correct answer: The source's internal (Thevenin) resistance

Maximum power transfer theorem states maximum power is delivered when RL = Rth (source internal resistance).

Question 23: When measuring a transistor's beta (hFE) with a DMM in transistor test mode, the reading is 0. This indicates:

The transistor is a PNP type and needs reversed leads
The DMM range is set too low
The transistor's base-emitter junction is open or the device is faulty (Correct answer)
The transistor requires a higher base current for the test

Correct answer: The transistor's base-emitter junction is open or the device is faulty

A beta reading of 0 indicates the transistor cannot amplify current, pointing to an open base-emitter junction or a completely failed device.

Question 24: What is the primary advantage of a Darlington pair transistor configuration?

Very high current gain (β² ≈ β1 × β2) (Correct answer)
Reduced power consumption
Lower noise figure
Very high frequency response

Correct answer: Very high current gain (β² ≈ β1 × β2)

A Darlington pair cascades two BJTs so their betas multiply, yielding an extremely high overall current gain equal to approximately β1 × β2.

Question 25: What is the phase angle between voltage and current in a purely capacitive AC circuit?

Current lags voltage by 45°
Voltage leads current by 90°
Current leads voltage by 90° (Correct answer)
Current and voltage are in phase

Correct answer: Current leads voltage by 90°

In a purely capacitive circuit, current leads the voltage by 90 degrees.

Question 26: Which type of counter produces a modulus that is not a power of two by using feedback to skip states?

Johnson counter
Ring counter
Modulo-N counter (Correct answer)
Ripple counter

Correct answer: Modulo-N counter

A modulo-N counter uses decode-and-reset or feedback logic to count to N−1 then recycle, regardless of whether N is a power of two.

Question 27: Which component provides clock signals to synchronize operations in a microprocessor?

Decoder
ALU
RAM
Clock Generator (Correct answer)

Correct answer: Clock Generator

Microprocessors require precise timing to synchronize all internal operations. The clock generator produces a continuous series of electrical pulses, known as clock signals, which dictate the speed and timing of data transfers and instruction execution within the CPU. Without these synchronized pulses, the various components of the microprocessor would not be able to coordinate their actions effectively.

Question 28: Transformer voltage regulation (VR%) is calculated based on the change in secondary voltage between:

Cold startup and steady-state thermal equilibrium
Full-load and maximum overload conditions
Minimum and maximum input voltage at constant load
No-load and full-load conditions at rated input voltage (Correct answer)

Correct answer: No-load and full-load conditions at rated input voltage

Transformer VR% = ((Vno-load − Vfull-load) / Vfull-load) × 100%, measuring the voltage rise when load is removed due to internal impedance.

Question 29: The Q factor (quality factor) of a series resonant circuit is best described as:

The ratio of resonant frequency to bandwidth (Correct answer)
The ratio of reactive power to true power
The ratio of bandwidth to resonant frequency
The ratio of resistance to reactance

Correct answer: The ratio of resonant frequency to bandwidth

Q = fr/BW, representing how selective (narrow-bandwidth) the resonant circuit is.

Question 30: A signal generator's output impedance is specified at 50 Ω. To avoid reflections and achieve maximum power transfer to the load, the load impedance should be:

100 Ω
As high as possible (open circuit)
50 Ω (Correct answer)
0 Ω (short circuit)

Correct answer: 50 Ω

Maximum power transfer and reflection-free operation occur when load impedance matches source impedance.

Question 31: Which setting on a DMM should be used when measuring the forward voltage drop of a diode?

Diode test mode (Correct answer)
DC voltage range
Continuity mode
Resistance (ohms) range

Correct answer: Diode test mode

The diode test mode applies a small forward current and displays the forward voltage drop, providing a definitive diode junction check.

Question 32: What is propagation delay in a logic gate?

The setup time of a flip-flop
The gate's noise immunity threshold
Time for the output to settle after an input change (Correct answer)
The frequency of the clock signal

Correct answer: Time for the output to settle after an input change

Propagation delay (tpd) is the time interval between a change at the input and the resulting change at the output of a gate.

Question 33: To find the Thevenin resistance of a circuit containing only independent sources, you should:

Measure voltage at the terminals
Double the load resistance
Short circuit the terminals and measure current
Deactivate all sources and measure resistance at the terminals (Correct answer)

Correct answer: Deactivate all sources and measure resistance at the terminals

Rth is found by deactivating all independent sources and calculating the resistance seen from the open terminals.

Question 34: When a silicon diode is forward biased, the typical voltage drop across it is approximately:

0.3 V
0.7 V (Correct answer)
0.1 V
1.2 V

Correct answer: 0.7 V

Silicon diodes have a forward voltage drop of approximately 0.7 V, while germanium diodes drop about 0.3 V.

Question 35: A 4-bit binary ripple counter has a maximum count of:

14
8
15 (Correct answer)
16

Correct answer: 15

A 4-bit counter counts from 0000 to 1111 (0–15), giving 16 states with a maximum count of 15.

Question 36: Which type of ROM can be erased by exposure to ultraviolet light?

Mask ROM
EPROM (Correct answer)
PROM
EEPROM

Correct answer: EPROM

EPROM (Erasable Programmable ROM) is erased by exposing its quartz window to UV light for several minutes.

Question 37: A zener diode is primarily used in circuits for:

Current amplification
Voltage regulation (Correct answer)
Signal amplification
Frequency filtering

Correct answer: Voltage regulation

Zener diodes are designed to operate in reverse breakdown to maintain a stable reference voltage.

Question 38: What is the purpose of a priority encoder?

Detects parity errors
Selects one of many data sources
Outputs the binary code of the highest-priority active input (Correct answer)
Converts binary to BCD

Correct answer: Outputs the binary code of the highest-priority active input

A priority encoder resolves simultaneous inputs by outputting the binary address of the highest-priority (typically highest-numbered) active input.

Question 39: The bandwidth of a series resonant circuit with fr = 500 kHz and Q = 50 is:

100 kHz
10 kHz (Correct answer)
1 kHz
25 kHz

Correct answer: 10 kHz

BW = fr/Q = 500 kHz / 50 = 10 kHz.

Question 40: A technician suspects a leaky electrolytic capacitor. Which symptom best supports this diagnosis?

No deflection on ohmmeter needle
Lower than expected resistance reading on ohmmeter (Correct answer)
Correct capacitance value on LCR meter
Infinite resistance in both directions

Correct answer: Lower than expected resistance reading on ohmmeter

A leaky capacitor has internal resistance paths causing lower-than-expected resistance readings, indicating dielectric breakdown.

Question 41: In a DC series circuit containing three resistors (R1=10Ω, R2=20Ω, R3=30Ω), what is the total resistance (Rt)?

5.45 Ω
20 Ω
60 Ω (Correct answer)
600 Ω

Correct answer: 60 Ω

For resistors connected in series, the total resistance is the sum of the individual resistances. Therefore, Rt = R1 + R2 + R3 = 10Ω + 20Ω + 30Ω = 60Ω.

Question 42: A zener diode in a voltage regulator circuit measures 0 V across it under load. What fault is indicated?

Zener is open
Zener is operating normally
Load resistance is too high
Zener is shorted (Correct answer)

Correct answer: Zener is shorted

A shorted zener diode will drop 0 V, collapsing the regulated output voltage to near zero.

Question 43: Thevenin's theorem replaces a complex network with which equivalent circuit?

Two resistors in series
A capacitor and resistor in parallel
A voltage source in series with a resistance (Correct answer)
A current source in parallel with a resistance

Correct answer: A voltage source in series with a resistance

Thevenin's theorem reduces any linear two-terminal network to a single voltage source (Vth) in series with a resistance (Rth).

Question 44: What is the primary purpose of power factor correction in industrial AC systems?

To increase the resonant frequency of the system
To reduce reactive power demand and improve efficiency (Correct answer)
To increase the impedance seen by the source
To raise the supply voltage level

Correct answer: To reduce reactive power demand and improve efficiency

Power factor correction (typically using capacitor banks) reduces reactive power, lowering apparent power demand and reducing I²R losses in the distribution system.

Question 45: What is the voltage across an open-circuit branch in a parallel circuit if the source is 15V?

Infinite
15V (Correct answer)
0V
7.5V

Correct answer: 15V

All branches in a parallel circuit share the same voltage as the source; the open branch still has the full 15V across it.

Question 46: In a series circuit with a 9V battery and three equal resistors, each resistor drops which voltage?

9V
3V (Correct answer)
27V
1V

Correct answer: 3V

In a series circuit, voltage divides equally across identical resistors: 9V / 3 = 3V each.

Question 47: What is the function of a microprocessor in a digital system?

Maintains internet connectivity.
Controls and processes digital operations (Correct answer)
Stores large amounts of data.
Provides power to all components.

Correct answer: Controls and processes digital operations

A microprocessor is the central processing unit (CPU) of a computer, integrated onto a single integrated circuit. Its main function is to execute instructions, perform arithmetic and logical operations, and control the overall flow of data and operations within a digital system. It acts as the 'brain' that processes information and manages system components.

Question 48: What is the key difference between a latch and a flip-flop in digital sequential circuits?

Latches are level-triggered, while flip-flops are edge-triggered. (Correct answer)
Latches operate asynchronously, while flip-flops operate synchronously.
Latches are made from logic gates, while flip-flops are not.
Latches can store more bits of data than flip-flops.

Correct answer: Latches are level-triggered, while flip-flops are edge-triggered.

The fundamental difference lies in their triggering mechanism. A latch is level-triggered, meaning its output can change whenever the enable signal is active (e.g., HIGH). A flip-flop is edge-triggered, meaning its output only changes at the moment the clock signal transitions from low-to-high (rising edge) or high-to-low (falling edge).

Question 49: A transformer has a primary winding of 200 turns and a secondary winding of 50 turns. If 120V AC is applied to the primary, what is the secondary voltage?

30V (Correct answer)
60V
480V
240V

Correct answer: 30V

Using the turns ratio: Vs = Vp × (Ns/Np) = 120 × (50/200) = 30V.

Question 50: In AC circuit analysis, Kirchhoff's Voltage Law (KVL) applies to:

Only resistive AC circuits
Phasor (complex) voltages around a loop (Correct answer)
Only DC circuits
Only series circuits, not parallel

Correct answer: Phasor (complex) voltages around a loop

KVL applies to AC circuits using phasor (complex number) representation, so phasor voltages around any closed loop sum to zero.

Question 51: What is the resonant frequency of a series LC circuit with L = 10 mH and C = 10 µF?

approximately 503 Hz (Correct answer)
approximately 1592 Hz
approximately 50 Hz
approximately 159 Hz

Correct answer: approximately 503 Hz

fr = 1/(2π√LC) = 1/(2π√(0.01 × 0.00001)) ≈ 503 Hz.

Question 52: In a common-emitter BJT amplifier, which parameter is primarily responsible for the upper cutoff frequency limitation at high frequencies?

Emitter bypass capacitor
Power supply impedance
Base spreading resistance only
Miller-multiplied collector-base capacitance (Cµ) (Correct answer)

Correct answer: Miller-multiplied collector-base capacitance (Cµ)

The Miller effect multiplies the collector-base capacitance Cµ by (1 + |Av|), creating a dominant pole that limits high-frequency response.

Question 53: Three resistors of 10Ω, 20Ω, and 30Ω are connected in parallel. What is the equivalent resistance?

5.45Ω (Correct answer)
3.33Ω
60Ω
20Ω

Correct answer: 5.45Ω

For parallel resistors, 1/Req = 1/10 + 1/20 + 1/30 = 6/60 + 3/60 + 2/60 = 11/60, so Req ≈ 5.45Ω.

Question 54: A circuit has a 24V source with two resistors in series: 6Ω and 18Ω. What is the voltage across the 18Ω resistor?

18V (Correct answer)
6V
12V
24V

Correct answer: 18V

Using the voltage divider: V18 = 24 × (18 / (6+18)) = 24 × 0.75 = 18V.

Question 55: The superposition theorem applies only to circuits that are:

Linear and bilateral (Correct answer)
DC only
Nonlinear and unilateral
Purely resistive only

Correct answer: Linear and bilateral

Superposition requires linearity (responses proportional to inputs) and works on bilateral circuits with multiple independent sources.

Question 56: A technician is troubleshooting a linear DC power supply and observes excessive 60/120 Hz AC ripple on the output using an oscilloscope. The DC output voltage is present but is lower than specified. Which component failure is the most likely cause of these symptoms?

A shorted Zener diode in the regulator section
A shorted rectifier diode
An open-circuited transformer primary
An open or dried-out main filter capacitor (Correct answer)

Correct answer: An open or dried-out main filter capacitor

The main filter capacitor's function is to smooth the pulsating DC from the rectifier into a steady DC voltage. If this capacitor fails open or loses its capacitance (dries out), it can no longer effectively store and release charge, allowing the AC ripple from the rectifier to pass through to the output. [9] A shorted diode would likely blow a fuse or cause a zero-volt output. An open transformer primary would result in no output at all. A shorted Zener diode would pull the output voltage down to nearly zero.

Question 57: Which doping profile produces an abrupt p-n junction as opposed to a graded junction?

Ion implantation with a step-function profile at the metallurgical junction (Correct answer)
Thermal diffusion from a limited source
Diffusion doping with a Gaussian profile
Epitaxial growth with linearly varying doping

Correct answer: Ion implantation with a step-function profile at the metallurgical junction

A step-function (abrupt) doping change at the metallurgical junction, achievable with ion implantation, defines an abrupt p-n junction.

Question 58: What does the term 'skin effect' refer to in AC circuits?

Tendency of AC current to flow near the conductor surface at high frequencies (Correct answer)
Capacitive coupling between conductors
Insulation breakdown at high voltages
Impedance mismatch at circuit boundaries

Correct answer: Tendency of AC current to flow near the conductor surface at high frequencies

The skin effect causes AC current to concentrate near the outer surface of a conductor as frequency increases, effectively reducing the conductive cross-section.

Question 59: Which logic family is characterized by very low power consumption and high noise immunity, making it dominant in modern ICs?

TTL
CMOS (Correct answer)
ECL
RTL

Correct answer: CMOS

CMOS draws negligible static current and offers wide noise margins, making it the standard for modern digital ICs.

Question 60: Which number system uses base 16 with digits 0–9 and letters A–F?

Hexadecimal (Correct answer)
BCD
Binary
Octal

Correct answer: Hexadecimal

Hexadecimal (base-16) uses digits 0–9 and letters A–F to represent values 0 through 15.

Question 61: Which statement correctly describes the relationship between EMF and terminal voltage of a battery under load?

Terminal voltage is less than EMF due to internal resistance drop (Correct answer)
Terminal voltage equals EMF regardless of load
Terminal voltage is greater than EMF under load
EMF decreases as load increases

Correct answer: Terminal voltage is less than EMF due to internal resistance drop

Under load, current through internal resistance causes a voltage drop, making terminal voltage = EMF − I×r.

Question 62: What does a Bode plot primarily display for an AC circuit?

Gain and phase response versus frequency (Correct answer)
Power dissipation versus load resistance
Phasor diagrams at a single frequency
Time-domain waveforms

Correct answer: Gain and phase response versus frequency

A Bode plot shows how the gain (magnitude) and phase of a circuit's transfer function vary with frequency, typically using a logarithmic frequency axis.

Question 63: What logic function does a full adder perform that a half adder cannot?

Subtract two bits
Produce a carry-out
Handle negative numbers
Accept a carry-in from a previous stage (Correct answer)

Correct answer: Accept a carry-in from a previous stage

A full adder has three inputs (A, B, Carry-in), allowing it to be cascaded for multi-bit addition unlike a half adder.

Question 64: When measuring a 10 kΩ resistor in-circuit with a digital multimeter, the reading is stable at 4.7 kΩ. Assuming the multimeter and the resistor's marked value are correct, what is the most probable explanation for this reading?

The multimeter's battery is low, causing an inaccurate reading.
The resistor has failed and its value has decreased by more than 50%.
The circuit's power was accidentally left on during the measurement.
Another component or circuit path is in parallel with the resistor being measured. (Correct answer)

Correct answer: Another component or circuit path is in parallel with the resistor being measured.

When measuring resistance in a circuit, the multimeter applies a small voltage and measures the resulting current. If other components are in parallel with the resistor under test, they provide an alternate path for the current, resulting in a total measured resistance that is lower than the actual value of the resistor. [8, 11] This is a common pitfall in component-level troubleshooting, often requiring one lead of the component to be lifted from the board for an accurate measurement.

Question 65: A ceramic disc capacitor reads zero ohms on an ohmmeter. What does this indicate?

The capacitor has high leakage
The capacitor is shorted (Correct answer)
The capacitor is open
The capacitor is functioning normally

Correct answer: The capacitor is shorted

A zero-ohm reading on a non-electrolytic capacitor indicates a short circuit, as these capacitors should read very high or infinite resistance.

Question 66: A low-pass RC filter has R = 1 kΩ and C = 0.1 µF. What is its cutoff frequency?

approximately 1592 Hz (Correct answer)
approximately 6283 Hz
approximately 15,920 Hz
approximately 159 Hz

Correct answer: approximately 1592 Hz

fc = 1/(2πRC) = 1/(2π × 1000 × 0.0000001) ≈ 1592 Hz.

Question 67: A Zener diode is operating in reverse breakdown at 6.2 V with 20 mA flowing through it. What is the power dissipated?

0.31 W
3.1 W
0.124 W (Correct answer)
124 W

Correct answer: 0.124 W

Power = V × I = 6.2 V × 0.020 A = 0.124 W.

Question 68: Power dissipation in a linear series pass regulator is primarily determined by:

Forward voltage drop across the output filter diodes
ESR of the output filter capacitors
The transformer core loss and copper winding resistance
The voltage difference between input and output multiplied by load current (Correct answer)

Correct answer: The voltage difference between input and output multiplied by load current

Power dissipated in the pass transistor equals Pd = (Vin − Vout) × Iload, which is why linear regulators become very inefficient when the voltage drop is large.

Question 69: A 12V source delivers 36W to a load. What current flows through the load?

3A (Correct answer)
4A
432A
0.33A

Correct answer: 3A

P = V × I, so I = P/V = 36W / 12V = 3A.

Question 70: A capacitor is rated 47 µF, 50V AC. Operating it at 60V would most likely cause:

Improved power factor
Dielectric breakdown and possible failure (Correct answer)
Reduced capacitive reactance
Increased capacitance

Correct answer: Dielectric breakdown and possible failure

Exceeding the voltage rating stresses the dielectric, risking breakdown and permanent damage to the capacitor.

Question 71: A 12V battery with an internal resistance of 0.5Ω supplies current to a 5.5Ω external resistor. What is the terminal voltage?

10V
12V
6V
11V (Correct answer)

Correct answer: 11V

Current = 12V / (0.5 + 5.5) = 2A; terminal voltage = 12 - (2 × 0.5) = 11V.

Question 72: What is the output of a NAND gate when both inputs are HIGH?

Undefined
HIGH
LOW (Correct answer)
Tri-state

Correct answer: LOW

A NAND gate outputs LOW only when all inputs are HIGH, making it the complement of an AND gate.

Question 73: In a D flip-flop, what happens to the output Q on the active clock edge when D = 0?

Q retains its previous value
Q becomes 0 (Correct answer)
Q becomes 1
Q toggles

Correct answer: Q becomes 0

A D flip-flop transfers the D input directly to Q on the active clock edge, so Q = 0 when D = 0.

Question 74: Which device is used to control current in a circuit?

Transistor (Correct answer)
Resistor
Diode
Capacitor

Correct answer: Transistor

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It can act as an electronic switch, allowing or blocking current flow based on a small input signal applied to its control terminal. This ability to control larger currents with smaller ones makes transistors fundamental components in modern electronics, from microprocessors to amplifiers.

Question 75: Load regulation of a power supply is best defined as:

The ripple voltage divided by the DC output voltage
The change in output voltage from no-load to full-load conditions (Correct answer)
The efficiency at rated full-load current
The output current capability at minimum input voltage

Correct answer: The change in output voltage from no-load to full-load conditions

Load regulation = ((Vno-load − Vfull-load) / Vfull-load) × 100%, indicating how well the supply maintains its output voltage as current demand changes.

CETa Associate Level Certification

The CETa Associate Level Certification validates fundamental knowledge in electronics technology, suitable for entry-level technicians.

Questions

120 min

Time Limit

75%

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