1. The primary function of a voltage regulator is to:
A. Convert DC to AC
B. Convert AC to DC
C. Maintain a constant output voltage regardless of input fluctuations
D. Increase the input voltage
Answer: C. Maintain a constant output voltage regardless of input fluctuations
2. A linear voltage regulator typically uses:
A. High frequency switching
B. A pass transistor that dissipates excess power as heat
C. A transformer to step up the voltage
D. A capacitor to store energy
Answer: B. A pass transistor that dissipates excess power as heat
3. The output voltage of a linear voltage regulator is:
A. Always higher than the input voltage
B. Always equal to the input voltage
C. Always lower than the input voltage
D. Constant and independent of the input voltage
Answer: D. Constant and independent of the input voltage
4. The LM317 is an example of which type of voltage regulator?
A. Switching regulator
B. Linear regulator
C. Zener regulator
D. Buck converter
Answer: B. Linear regulator
5. Which of the following is a characteristic of a switching voltage regulator?
A. It produces less heat compared to linear regulators
B. It always provides a lower output voltage than the input
C. It uses resistors to control the output voltage
D. It requires more complex circuitry compared to linear regulators
Answer: A. It produces less heat compared to linear regulators
6. A voltage regulator with an adjustable output voltage typically has:
A. A fixed resistor in its feedback loop
B. A feedback control system that adjusts the output
C. An internal oscillator to generate different voltages
D. A transformer that automatically adjusts voltage
Answer: B. A feedback control system that adjusts the output
7. Which of the following is NOT a type of voltage regulator?
A. Zener diode regulator
B. Linear voltage regulator
C. Switching voltage regulator
D. Parallel resistor regulator
Answer: D. Parallel resistor regulator
8. A voltage stabilizer is used to:
A. Maintain a constant input voltage
B. Convert AC to DC
C. Maintain a constant output voltage when input fluctuates
D. Increase the voltage when it drops
Answer: C. Maintain a constant output voltage when input fluctuates
9. A typical voltage stabilizer uses a component called a:
A. Capacitor
B. Zener diode
C. Inductor
D. Transformer
Answer: B. Zener diode
10. The primary difference between a voltage regulator and a voltage stabilizer is that:
A. A voltage stabilizer is used for AC applications, while a voltage regulator is used for DC applications
B. A voltage regulator provides constant voltage, while a stabilizer adjusts voltage automatically for both low and high input levels
C. A voltage stabilizer provides a more accurate output voltage
D. A voltage stabilizer is only used in high-power systems
Answer: B. A voltage regulator provides constant voltage, while a stabilizer adjusts voltage automatically for both low and high input levels
11. A voltage stabilizer for home appliances typically uses:
A. A relay to cut off power when voltage is too high
B. A high-speed microcontroller to monitor voltage levels
C. A transformer and a capacitor to smooth the output
D. A Zener diode to regulate the voltage
Answer: C. A transformer and a capacitor to smooth the output
12. In an automatic voltage stabilizer, the relay control mechanism is typically used to:
A. Change the voltage levels automatically
B. Disconnect the device when the voltage exceeds a certain level
C. Provide DC output to the load
D. Convert AC into DC
Answer: B. Disconnect the device when the voltage exceeds a certain level
13. A constant voltage transformer (CVT) is often used as a voltage stabilizer because it:
A. Converts the input voltage into a regulated DC voltage
B. Ensures a constant output voltage, regardless of load variations
C. Provides high-efficiency DC power
D. Has a lower operating cost than other voltage stabilizers
Answer: B. Ensures a constant output voltage, regardless of load variations
14. The use of a voltage stabilizer is crucial when there are:
A. Frequent and significant fluctuations in the input voltage
B. Steady input voltage with no variations
C. Only slight differences in voltage levels
D. High demand for electrical current
Answer: A. Frequent and significant fluctuations in the input voltage
15. The working principle of a stabilizer that uses a servo motor is based on:
A. Automatically adjusting the voltage by turning a variable transformer
B. Using a capacitor to store and release energy
C. Switching between different resistors to adjust the output
D. Using a diode to clamp the voltage at a fixed level
Answer: A. Automatically adjusting the voltage by turning a variable transformer
16. The efficiency of a voltage stabilizer can be significantly impacted by:
A. The size of the transformer used
B. The ambient temperature
C. The load connected to the stabilizer
D. All of the above
Answer: D. All of the above
17. In a voltage stabilizer, the “cut-off” feature is used to:
A. Regulate the output voltage
B. Prevent excessive voltage from reaching the load
C. Monitor the power usage
D. Ensure smooth voltage transitions
Answer: B. Prevent excessive voltage from reaching the load
18. A stabilizer for an air conditioner generally helps in:
A. Ensuring the compressor motor works optimally despite fluctuating voltage
B. Filtering noise from the input power
C. Providing constant DC to the unit
D. Reducing the energy consumption of the unit
Answer: A. Ensuring the compressor motor works optimally despite fluctuating voltage
19. In an electronic voltage regulator, the most common control mechanism for maintaining output voltage is:
A. Linear feedback
B. Pulse-width modulation
C. Series switching
D. Capacitor regulation
Answer: B. Pulse-width modulation
20. In a power supply system, which of the following is an advantage of using a voltage regulator?
A. It increases the power consumption
B. It improves the performance and lifespan of electronic devices
C. It reduces the power factor
D. It directly converts AC to DC
Answer: B. It improves the performance and lifespan of electronic devices