Unlock hundreds more features
Save your Quiz to the Dashboard
View and Export Results
Use AI to Create Quizzes and Analyse Results

OR
Sign inSign in with Facebook
Sign inSign in with Google
Quizzes > Computers & Technology > Electronics & Gadgets

Master the ATX Power Supply Quiz and Test Your Skills!

Ready for ATX power supply trivia? Dive in and prove your PSU prowess!

Difficulty: Moderate
2-5mins
Learning OutcomesCheat Sheet
Paper art illustration of an ATX power supply with voltage rail symbols connectors and quiz prompt on sky blue background

Ready to prove your mettle with our ATX power supply quiz? Whether you're a seasoned PC builder or an aspiring tech guru, this free challenge will test your grasp of voltage rail tolerances, connector pinouts and troubleshooting tactics. From understanding 12V rails and standby voltages to mastering real-world repair scenarios, you'll measure your readiness for DIY builds and repairs. Dive into this computer power supply quiz to unlock practical insights, sharpen your ATX power supply trivia skills, and see if you can ace an ATX PSU test that mirrors real-world setups. Hungry for more nuts-and-bolts brain-teasers? Explore our electrical questions and answers or level up with this computer hardware quiz. Gear up, click start and master your power supply knowledge quiz today!

What does ATX stand for?
Automated Transfer eXchange
Advanced Tech Express
Automated Technical Exchange
Advanced Technology eXtended
ATX is an acronym for Advanced Technology eXtended, defining a motherboard and power supply specification introduced by Intel in 1995. It replaced the earlier AT standard by improving ease of use, component placement, and power management. The standard continues to evolve, with variants like ATX12V addressing modern system requirements. More info
Which wire color on an ATX connector indicates the +12V rail?
Orange
Yellow
Blue
Red
In ATX power supplies, yellow wires are used for the +12V rail, supplying power to CPU and peripheral components. Red wires indicate +5V, orange is +3.3V, and blue is ?12V. Correct wire coloring ensures proper voltage distribution. More info
What is the standby voltage provided by the +5VSB rail?
+5 volts
+3.3 volts
?5 volts
+12 volts
The +5VSB rail supplies a +5 volt standby output that remains live even when the main supply is off, enabling functions like Wake-on-LAN and system standby. It powers essential control circuits until the system fully shuts down or starts up. Maintaining a stable +5V standby is crucial for modern power management features. More info
How many pins are on the standard full-size ATX motherboard connector?
24
18
26
20
Modern ATX motherboards use a 24-pin main power connector, an extension of the original 20-pin design to provide additional power for multi-core CPUs and expansion cards. The extra four pins handle additional grounds and voltages to improve stability. Some older or budget boards still use the 20-pin version. More info
Which color wire corresponds to the +3.3V output on an ATX connector?
Orange
Purple
Red
Yellow
Orange wires on ATX connectors carry the +3.3V rail, often used by memory modules and chipset circuits. Red wires are +5V, yellow are +12V, and purple is the +5VSB standby line. Knowing wire colors helps avoid mis-wiring and damaging components. More info
What voltages does the Molex peripheral connector provide?
+12V and +5V
+12V and +3.3V
+5V and +3.3V
+3.3V and +5VSB
The Molex peripheral (4-pin) connector provides +12V on the yellow wire and +5V on the red wire, with two black ground wires. It is commonly used to power older hard drives, optical drives, and fans. It does not supply +3.3V, which is found on newer SATA connectors. More info
What is the primary purpose of the PS_ON signal in an ATX power supply?
To regulate the +12V rail
To control the fan speed
To turn the PSU on when pulled low
To signal the motherboard to sleep
PS_ON is a control input from the motherboard to the PSU; when pulled low, it tells the power supply to turn on its main outputs. If left high (open), only the +5VSB rail remains active. This allows the system to control power without manual intervention. More info
The Power Good (PWR_OK) signal indicates what condition?
PS_ON is pulsed low
The fan is spinning
All voltage rails are stable
The standby voltage is present
When the PSU has stabilized its output voltages and they are within specified tolerances, it asserts the Power Good signal, allowing the motherboard to begin the POST process. If voltages drop out of range, PWR_OK is deasserted, causing a reset or shutdown. This protects components from undervoltage and overvoltage conditions. More info
Which wire color carries the ?12V output on an ATX connector?
Yellow
Gray
Blue
Black
Blue wires on ATX connectors denote the ?12V rail, originally used for serial port level shifting and legacy circuits. Its use is minimal in modern PCs, but it's still specified for compatibility. Black wires are grounds, and gray is Power Good. More info
What feature allows a computer to wake up via network packets?
Power Good signal
PS_ON signal pulsing
Active PFC circuit
Wake-on-LAN powered by +5VSB
Wake-on-LAN uses the +5VSB standby rail to power the network interface card even when the system is off. When a magic packet arrives, the NIC signals the motherboard to pull PS_ON low, starting the PSU. This allows remote system wake-up capabilities. More info
Which pinout change differentiates ATX12V v2.x from earlier versions on the main connector?
Presence of four 12V wires added
Removal of the +3.3V rail
Extension of PS_ON to two pins
Addition of an eighth ground pin
ATX12V v2.x supplies additional +12V capacity by adding extra yellow +12V wires to the main 24-pin connector, meeting the needs of multi-core CPUs and GPUs. Earlier versions relied more on +3.3V and +5V rails. This change enhances current delivery and stability. More info
How many pins are on the EPS12V CPU power connector?
4
10
6
8
The EPS12V standard uses an 8-pin (4+4) CPU power connector, delivering additional +12V capacity for server and high-end desktop processors. It supplements the main 24-pin connector with dedicated CPU power. Older motherboards used a 4-pin 12V connector, but modern designs favor the 8-pin arrangement. More info
What is the pin count of a standard SATA power connector?
6
12
15
7
Standard SATA power connectors have 15 pins, providing three voltage rails: +3.3V, +5V, and +12V, each with multiple pins for current capacity. This design replaced the older Molex peripheral connector for drives. Some manufacturers omit the +3.3V line, but the connector remains 15-pin. More info
What does the PWRBTN signal control?
Voltage regulation loop
Fan speed ramping
Soft power switch function
Standby rail output
The PWRBTN signal connects the front panel power button to the motherboard, allowing the user to send a soft power-on or power-off command. The firmware interprets the signal and, via PS_ON, controls the main power rails. Long presses can trigger forced shutdown sequences. More info
What is the main difference between 20-pin and 24-pin ATX connectors?
Inclusion of a second PS_ON pin
Removal of the ?12V rail
Four extra pins for improved 12V distribution
Addition of +5VSB rail pins
The 24-pin connector adds four pins - two grounds and two +12V wires - to the original 20-pin layout, providing higher current capacity and better voltage stability for modern components. The +5VSB rail and ?12V rail remain unchanged. This evolution meets increased power demands. More info
What does 'hold-up time' refer to in ATX PSU specifications?
Duration of standby power
Time PSU maintains output after AC loss
Time to reach full load
Delay before fan starts
Hold-up time is the duration an ATX power supply can maintain its regulated outputs within tolerance after an AC mains failure, typically at least 16 ms per ATX spec. It ensures systems don't crash during brief disturbances. Capacitor sizing in the PSU determines this time. More info
Which component in an ATX PSU primarily filters high-frequency noise before it reaches the AC mains?
SMPS transformer
EMI filter
PFC choke
Output capacitors
The EMI (electromagnetic interference) filter on the AC input of an ATX power supply suppresses high-frequency noise generated by the switching circuitry, protecting the mains from interference. It typically consists of capacitors and inductors arranged to block unwanted frequencies. Proper filtering ensures compliance with EMC regulations. More info
What topology is most commonly used for active power factor correction in ATX supplies?
Buck converter
Boost converter
Forward converter
Flyback converter
Active PFC in ATX supplies typically uses a boost converter topology on the input stage to raise the rectified DC voltage and shape the current draw to be in phase with the mains voltage. This improves efficiency and reduces input current distortion. Other topologies are less common for PFC. More info
What does an 80 Plus certification indicate about a power supply?
Passes EMI testing without filter
At least 80% efficiency at key load levels
Supports four different voltage rails
Has active PFC built-in
80 Plus certification ensures that a power supply achieves at least 80% efficiency at 20%, 50%, and 100% of rated load, reducing wasted energy and heat. Higher levels (Bronze, Silver, Gold, Platinum, Titanium) demand greater efficiency thresholds. It does not mandate specific rail designs or PFC. More info
What is cross-regulation in multi-rail power supply designs?
Sequential startup of voltage rails
Interaction between loaded rails affecting each other's voltage
Feedback loop for active PFC
Phase shift between primary windings
Cross-regulation refers to the phenomenon where changes in load on one secondary rail affect the voltages on other rails due to shared transformer and regulation constraints. Designers mitigate this by careful transformer design and post-regulation circuits. High loads on one rail can pull down others if not controlled. More info
Which protection circuit trips when a rail draws excessive current?
Overtemperature Protection (OTP)
Overvoltage Protection (OVP)
Overcurrent Protection (OCP)
Undervoltage Protection (UVP)
OCP, or Overcurrent Protection, monitors current on each rail and disables output if the current exceeds specified limits, preventing damage from shorts or excessive loads. This feature is mandatory for safe PSU operation. Other protections handle voltage and temperature faults. More info
What advantage does an LLC resonant converter provide in ATX power supplies?
Higher hold-up times without larger caps
Eliminates need for secondary regulation
Reduced switching losses and lower EMI
Simpler control compared to flyback
LLC resonant converters operate near zero-voltage switching, minimizing switching losses and electromagnetic interference (EMI). Their resonant tank reduces stress on switching devices, improving efficiency and thermal performance. They are common in high-efficiency ATX designs. More info
Typically, what switching frequency range is used in modern ATX primary converters?
1 - 2 MHz
50 - 100 kHz
1 - 10 kHz
500 - 600 Hz
Most modern ATX SMPS primary converters switch at 50 - 100 kHz, balancing transformer size and efficiency. Lower frequencies require larger transformers, while significantly higher frequencies increase switching losses. Some high-end designs push frequencies higher with advanced MOSFETs and resonant topologies. More info
What is the maximum ripple voltage allowed on the +12V rail per ATX12V specifications?
1 V peak-to-peak
120 mV peak-to-peak
50 mV peak-to-peak
200 mV peak-to-peak
ATX12V specs limit +12V rail ripple to 120 mV peak-to-peak under specified load conditions to ensure stable operation of CPUs and GPUs. Excessive ripple can cause system instability or component stress. Designers use bulk capacitors and low-ESR caps to meet these requirements. More info
According to ATX standards, what is the required transient response time for main rails?
Within 10 ms for a 10% load step
Within 0.5 ms for a 50% load step
Within 5 ms for a 5% load step
Within 2 ms for a 25% load step
The ATX12V specification requires main rails to recover within 2 ms when subjected to a 25% sudden load change, maintaining voltages within tolerance. This ensures processors and GPUs operate correctly during rapid workload shifts. Achieving this demands fast-feedback loops and adequate output capacitance. More info
Which EMI standard do ATX power supplies typically comply with in North America?
UL 60950
CE Mark
VCCI Class B
FCC Part 15
In North America, ATX power supplies must meet FCC Part 15 Class B requirements for conducted and radiated emissions to avoid interfering with other electronics. CE and VCCI apply in other regions, and UL 60950 covers safety, not EMI. Compliance ensures regulatory approval. More info
What is the typical operating ambient temperature range specified for most ATX PSUs?
10°C to 40°C
0°C to 50°C
-20°C to 60°C
?10°C to 70°C
Most ATX power supplies are rated for safe operation in ambient temperatures from 0°C to 50°C. Exceeding these limits can accelerate component aging or trigger overtemperature protection. Designers select thermal management components to handle this range reliably. More info
What does Overvoltage Protection (OVP) prevent in an ATX PSU?
Voltage drop under load
Excessive input current draw
Fan failure due to high temperature
Output voltages exceeding safe limits
OVP monitors each output rail and disables the power supply if any voltage exceeds specified thresholds, protecting downstream components from overvoltage damage. It usually latches off until a restart. This safeguard is critical for system integrity. More info
What role does Undervoltage Protection (UVP) play in an ATX power supply?
Delays PS_ON until stable
Prevents overcurrent faults
Shuts down if voltages fall below safe limits
Regulates fan speed
UVP monitors output rails for voltage dropping below defined thresholds under load. If a rail sags too far, the PSU will shut down or latch off to avoid data corruption or component malfunction. It complements OVP and OCP protections. More info
In ATX power states, what does S4 represent?
Hibernate with RAM off
Working state
Sleep with RAM powered
Soft off with standby power
S4, or hibernate state, saves system context to disk and turns off almost all power, including RAM. Only the +5VSB rail stays active for wake events. S4 consumes negligible power compared to S3 (sleep), where RAM remains powered. More info
What is line regulation in the context of ATX power supplies?
Fluctuation of output under load steps
Time taken to recover from overload
Change in output voltage with input voltage variation
Ripple introduced by switching
Line regulation measures how well a PSU maintains its output voltage when the AC input voltage varies over its specified range. Good line regulation (typically <±0.5%) ensures stable operation despite mains fluctuations. It is distinct from load regulation and transient response. More info
How is the Power Good (PWR_OK) signal typically generated after startup?
Derived from the +5VSB rail only
Monitored by a delay circuit after voltages stabilize
Generated by the CPU firmware
Sent immediately when PS_ON is pulled low
After PS_ON is asserted, the PSU ramps its outputs. A delay and voltage-monitoring circuit ensures all rails are within tolerance before asserting PWR_OK, typically 100 - 500 ms later. This prevents the motherboard from booting on unstable voltages. More info
What is the main purpose of remote sensing in ATX power supply design?
Compensate for voltage drop at the load
Measure input line voltage
Control the PFC stage
Detect fan speed variations
Remote sensing uses sense wires at the load end to measure actual voltage, allowing the PSU to adjust output and compensate for voltage drop across cables. This ensures precise voltage regulation at critical components like CPUs and GPUs. It is key in high-performance systems. More info
Why is the ESR of output capacitors critical for transient response in ATX PSUs?
ESR determines hold-up time
High ESR improves ripple filtering
ESR only affects EMI emissions
Low ESR reduces voltage droop during load steps
Equivalent Series Resistance (ESR) of capacitors affects how quickly charge can be delivered during sudden load changes. Low-ESR caps minimize voltage droop and ripple, improving transient response. High-ESR caps slow response and increase voltage overshoot or sag. More info
In a multi-rail +12V design, how does OCP behave when one rail exceeds its limit?
Shuts down the entire PSU immediately
Increases PWR_OK delay
Transfers current to other rails
Trips only that rail's protection circuit
Multi-rail OCP monitors each +12V rail separately; if one rail draws excessive current, only that rail's protection circuit trips. This prevents overloads on individual connectors without shutting down all outputs. Designers must balance rail loads to avoid nuisance trips. More info
0
{"name":"What does ATX stand for?", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"What does ATX stand for?, Which wire color on an ATX connector indicates the +12V rail?, What is the standby voltage provided by the +5VSB rail?","img":"https://www.quiz-maker.com/3012/images/ogquiz.png"}

Study Outcomes

  1. Identify ATX Power Supply Voltage Rails -

    After completing this ATX power supply quiz, you'll be able to recognize and name each voltage rail in a standard ATX unit, understanding their respective roles in powering PC components.

  2. Describe ATX PSU Connector Pinouts -

    You will learn to map out the key ATX power supply trivia by detailing the pinout configurations of 20-, 24-pin, and auxiliary connectors.

  3. Troubleshoot Common PSU Issues -

    By testing your power supply knowledge quiz skills, you'll be equipped to diagnose typical faults such as voltage fluctuations, fan failures, and startup problems.

  4. Calculate PSU Wattage Requirements -

    You'll apply basic calculations to determine total system load and select an appropriately rated ATX PSU for reliable performance.

  5. Differentiate ATX Standards and Form Factors -

    Through this ATX PSU test, you'll distinguish between various ATX specifications, form factors, and efficiency ratings to make informed upgrade choices.

  6. Apply Safe Handling Best Practices -

    After the quiz, you'll know essential safety protocols for installing, testing, and maintaining a computer power supply to protect both you and your PC components.

Cheat Sheet

  1. Voltage Rail Basics -

    ATX power supplies deliver regulated +3.3V, +5V and +12V rails within ±5% tolerance according to Intel's ATX12V specification. Remember the "3-5-12" mnemonic to quickly recall these voltages during an ATX power supply quiz or ATX PSU test. Understanding how each rail supports different PC components is essential for stable system operation.

  2. 24-Pin ATX Connector Pinout -

    The main 24-pin interface includes color-coded wires: orange for +3.3V, red for +5V, yellow for +12V, black for ground, and gray for the Power Good signal. Familiarize yourself with a pinout diagram to boost your score on computer power supply quiz questions and to simplify real-world builds. Visualizing each pin's function helps prevent miswiring and troubleshooting headaches.

  3. Auxiliary & Peripheral Connectors -

    CPUs use a 4-pin or 8-pin 12V connector (EPS12V), while GPUs draw power via 6-pin or 6+2-pin PCIe plugs; SATA power cables supply drives with +3.3V, +5V and +12V, and Molex connectors provide +5V and +12V for legacy devices. A handy phrase - "Molex Makes Older eXternal gear happy" - helps you remember its role during ATX power supply trivia. Mastering these connectors is key when troubleshooting or assembling a PC.

  4. Power Good Signal & Soft-Start Timing -

    The PS_ON# line must be asserted to activate the PSU, and once on, the Power Good (PG) signal goes high only after all voltage rails stabilize (typically within 100 - 500 ms per Intel guidelines). Testing PG timing with a multimeter or oscilloscope ensures proper soft-start behavior during your ATX power supply quiz. Correct PG operation prevents erratic boot issues and safeguards your motherboard.

  5. Safety Protections & Troubleshooting -

    Modern ATX PSUs include over-voltage, over-current, over-temperature, and short-circuit protections to guard against electrical faults. When taking a power supply knowledge quiz or diagnosing a dead system, use a digital multimeter to verify rail voltages under load rather than relying on the paperclip test. Recognizing OVP or OCP trips will help you pinpoint failures and maintain system reliability.

Make a Quiz (FREE) Copy & Edit This Quiz Create a Quiz with AI

Electronics & Gadgets Quizzes

Powered by: Quiz Maker