UPS (Uninterruptible Power Supplies) MCQs

What is the primary function of a UPS?
A. To increase voltage levels
B. To provide backup power during outages
C. To regulate the temperature of electronic devices
D. To convert AC to DC power

Answer: B
Which of the following is NOT a component of a UPS system?
A. Battery
B. Inverter
C. Cooling fan
D. Oscilloscope

Answer: D
A UPS protects connected devices from which of the following power issues?
A. Voltage surges
B. Power outages
C. Voltage sags
D. All of the above

Answer: D

Which type of UPS is most commonly used for small office setups?
A. Online UPS
B. Line-interactive UPS
C. Standby UPS
D. Double-conversion UPS

Answer: C
In an online UPS, the load is powered by the __________ under normal conditions.
A. AC mains
B. Battery
C. Inverter
D. Transformer

Answer: C

What is the role of an inverter in a UPS system?
A. To convert AC to DC
B. To charge the battery
C. To convert DC to AC
D. To regulate power frequency

Answer: C
What determines the runtime of a UPS system?
A. Battery capacity
B. Input voltage
C. Load on the UPS
D. Both A and C

Answer: D

Which of the following is the typical efficiency range of an online UPS?
A. 50-60%
B. 70-80%
C. 90-95%
D. 95-100%

Answer: C
What is the purpose of Automatic Voltage Regulation (AVR) in a UPS?
A. To provide continuous AC power
B. To maintain a steady output voltage
C. To prevent overcharging the battery
D. To protect against power surges

Answer: B

Which technology is used in modern UPS systems to improve efficiency?
A. Ferroresonant transformers
B. Pulse Width Modulation (PWM)
C. Silicon-controlled rectifiers (SCRs)
D. Relay-based switching

Answer: B