Question 1 of 28

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

Free from change over and transition problems

Supplies constant power output

Works on single phase or three phase supply

It gives constant output frequency

Question 1 of 28

Question 2 of 28

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

Static transformer

Ferrite core type transformer

Auto transformer

Ring core type transformer

Question 2 of 28

Question 3 of 28

3. Which principle the constant voltage transformer works?

Mutual induction principle

Self induction principle

Ferro-resonant principle

Fall in potential principle

Question 3 of 28

Question 4 of 28

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

Provide constant current charging

Provide freshening charge

Provide trickle charging

Provide constant potential method charging

Question 4 of 28

Question 5 of 28

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

Oscillator and amplifier stages

Oscillator and rectifier stages

Oscillator, amplifier and transformer output stages

Amplifier and transformer output stages

Question 5 of 28

Question 6 of 28

6. Which is frequency converter?

D.C choppers

Rectifiers

D.C to A.C converters

Cyclo converters

Question 6 of 28

Question 7 of 28

7. What is the full form of UPS?

Uniform Power Supply

Uninterrupted Power Supply

Unregulated Power Supply

Universal Power Supply

Question 7 of 28

Question 8 of 28

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

Electro copying

Electro plating

Electro chemical equivalent

Electrolysis

Question 8 of 28

Question 9 of 28

9. Which transformer is used in servo voltage stabilizer?

Constant voltage transformer

Step down transformer

Toroidal autotransformer

Step up transformer

Question 9 of 28

Question 10 of 28

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

Battery unit

Rectifier unit

Inverter unit

Controller unit

Question 10 of 28

Question 11 of 28

11. What is the full form of PWM?

Phase Wide Modulation

Pulse Wide Modulation

Pulse Width Modulation

Phase Width Modulation

Question 11 of 28

Question 12 of 28

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

Oscillator circuit

Rectifier circuit

Amplifier circuit

Feedback circuit

Question 12 of 28

Question 13 of 28

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

Main supply failure

Battery charger input fuse blown out

Incorrect over load settings

Loose connection in battery terminal

Question 13 of 28

Question 14 of 28

14. Where square wave inverters are used?

Computers

DVD players

General lighting

TV receiver

Question 14 of 28

Question 15 of 28

15. Which is the function of an inverter?

Converts D.C voltage into A.C voltage

Converts D.C voltage into higher D.C voltage

Converts A.C voltage into higher A.C voltage

Converts A.C voltage into D.C voltage

Question 15 of 28

Question 16 of 28

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

Increase the VA rating of UPS

Increase the AH capacity of battery

Maintain battery terminal voltage always 90% of rating

Decrease the AH capacity of battery

Question 16 of 28

Question 17 of 28

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

Step down AC from amplifier

Step up AC from amplifier

Step down input AC

Step up input AC

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Question 18 of 28

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

Grinder

Geyser

Pump motor

Television

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Question 19 of 28

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

Current divider network

Voltage divider network

Resistance temperature detector network

Tapped transformer network

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Question 20 of 28

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

228 V

216 V

233 V

211 V

Question 20 of 28

Question 21 of 28

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

Remain same

Becomes zero

Decrease

Increase

Question 21 of 28

Question 22 of 28

22. 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

1.5 V and 32 AH

6 V and 24 AH

4.5 V and 8 AH

Question 22 of 28

Question 23 of 28

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

Battery is short circuited

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

Fault in inverter circuit

Mains earthing is not proper

Question 23 of 28

Question 24 of 28

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

Multimeter

Voltmeter

Ammeter

Ohmmeter

Question 24 of 28

Question 25 of 28

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

Under voltage relay

Autostat

Output transformer

Over voltage relay

Question 25 of 28

Question 26 of 28

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

Amalgamation

Polarization

Local action

Buckling

Question 26 of 28

Question 27 of 28

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

Automatic voltage stabilizer

Manual stepped voltage stabilizer

Servo voltage stabilizer

Constant voltage transformer stabilizer

Question 27 of 28

Question 28 of 28

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

Battery get short circuited

Defective feedback circuit

Relay points are joined together

Input voltage is very high

Question 28 of 28