Question 1 of 28

1. Which feedback network is used for automatic voltage stabilizer?

Tapped transformer network

Voltage divider network

Current divider network

Resistance temperature detector network

Question 1 of 28

Question 2 of 28

2. Which principle the constant voltage transformer works?

Ferro-resonant principle

Mutual induction principle

Fall in potential principle

Self induction principle

Question 2 of 28

Question 3 of 28

3. Which part in UPS supplies continuous output voltage in case of input voltage failure?

Controller unit

Battery unit

Inverter unit

Rectifier unit

Question 3 of 28

Question 4 of 28

4. Which is the function of an inverter?

Converts D.C voltage into higher D.C voltage

Converts D.C voltage into A.C voltage

Converts A.C voltage into D.C voltage

Converts A.C voltage into higher A.C voltage

Question 4 of 28

Question 5 of 28

5. What is the purpose of output transformer in inverters?

Step up input AC

Step up AC from amplifier

Step down AC from amplifier

Step down input AC

Question 5 of 28

Question 6 of 28

6. Which electronic circuit is used in an automatic voltage stabilizer to produce constant output voltage?

Amplifier circuit

Oscillator circuit

Feedback circuit

Rectifier circuit

Question 6 of 28

Question 7 of 28

7. Which transformer is used in servo voltage stabilizer?

Step up transformer

Constant voltage transformer

Step down transformer

Toroidal autotransformer

Question 7 of 28

Question 8 of 28

8. What is the advantage of on-line UPS over offline UPS?

It gives constant output frequency

Works on single phase or three phase supply

Supplies constant power output

Free from change over and transition problems

Question 8 of 28

Question 9 of 28

9. Which type of output transformer is used in automatic voltage stabilizer?

Ferrite core type transformer

Auto transformer

Static transformer

Ring core type transformer

Question 9 of 28

Question 10 of 28

10. What is the type of A.C voltage stabilizer?

Constant voltage transformer stabilizer

Automatic voltage stabilizer

Servo voltage stabilizer

Manual stepped voltage stabilizer

Question 10 of 28

Question 11 of 28

11. Which is the cause for the fault if the output voltage of UPS is higher than normal?

Defective feedback circuit

Battery get short circuited

Input voltage is very high

Relay points are joined together

Question 11 of 28

Question 12 of 28

12. How the hard sulphation defect in secondary cell can be prevented?

Provide constant potential method charging

Provide constant current charging

Provide freshening charge

Provide trickle charging

Question 12 of 28

Question 13 of 28

13. What is the effect during loading of the cell, the current strength falls and become zero?

Amalgamation

Polarization

Buckling

Local action

Question 13 of 28

Question 14 of 28

14. Which electrical device is actuating the voltages in a stepped voltage stabilizer?

Under voltage relay

Autostat

Over voltage relay

Output transformer

Question 14 of 28

Question 15 of 28

15. What is the reason for having low back up time in UPS?

Ampere hour (A.H) capacity of battery is not sufficient

Battery is short circuited

Mains earthing is not proper

Fault in inverter circuit

Question 15 of 28

Question 16 of 28

16. Where square wave inverters are used?

TV receiver

General lighting

DVD players

Computers

Question 16 of 28

Question 17 of 28

17. Calculate the voltage and ampere/hour, if four cells rated as 1.5 V and 8 A.H are in parallel?

3 V and 16 AH

4.5 V and 8 AH

6 V and 24 AH

1.5 V and 32 AH

Question 17 of 28

Question 18 of 28

18. What is the reason for tripping the UPS with full load?

Main supply failure

Incorrect over load settings

Battery charger input fuse blown out

Loose connection in battery terminal

Question 18 of 28

Question 19 of 28

19. Which term refers that the mass of a substance liberated from an electrolyte by one coulomb of electricity?

Electro chemical equivalent

Electro copying

Electro plating

Electrolysis

Question 19 of 28

Question 20 of 28

20. Which instrument is used to check short circuit faults in electronic circuit in voltage stabilizer?

Multimeter

Ohmmeter

Ammeter

Voltmeter

Question 20 of 28

Question 21 of 28

21. What is the full form of PWM?

Pulse Width Modulation

Phase Wide Modulation

Phase Width Modulation

Pulse Wide Modulation

Question 21 of 28

Question 22 of 28

22. What are the important stages in a simple inverter?

Oscillator, amplifier and transformer output stages

Amplifier and transformer output stages

Oscillator and amplifier stages

Oscillator and rectifier stages

Question 22 of 28

Question 23 of 28

23. What is the full form of UPS?

Unregulated Power Supply

Uninterrupted Power Supply

Universal Power Supply

Uniform Power Supply

Question 23 of 28

Question 24 of 28

24. Which is frequency converter?

Cyclo converters

Rectifiers

D.C to A.C converters

D.C choppers

Question 24 of 28

Question 25 of 28

25. Which is the application of automatic stepped voltage stabilizer?

Television

Grinder

Geyser

Pump motor

Question 25 of 28

Question 26 of 28

26. How the backup time of UPS can be increased?

Decrease the AH capacity of battery

Increase the AH capacity of battery

Maintain battery terminal voltage always 90% of rating

Increase the VA rating of UPS

Question 26 of 28

Question 27 of 28

27. What is the effect in internal resistance of a discharged cell?

Remain same

Becomes zero

Decrease

Increase

Question 27 of 28

Question 28 of 28

28. What is the minimum permissible single phase working voltage, if the declared voltage is 240V as per ISI?

216 V

233 V

211 V

228 V

Question 28 of 28