Question 1 of 28

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

Input voltage is very high

Battery get short circuited

Defective feedback circuit

Relay points are joined together

Question 1 of 28

Question 2 of 28

2. What is the full form of UPS?

Uniform Power Supply

Uninterrupted Power Supply

Universal Power Supply

Unregulated Power Supply

Question 2 of 28

Question 3 of 28

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

Step down input AC

Step up AC from amplifier

Step up input AC

Step down AC from amplifier

Question 3 of 28

Question 4 of 28

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

6 V and 24 AH

1.5 V and 32 AH

3 V and 16 AH

4.5 V and 8 AH

Question 4 of 28

Question 5 of 28

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

Electro chemical equivalent

Electro plating

Electrolysis

Electro copying

Question 5 of 28

Question 6 of 28

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

Incorrect over load settings

Loose connection in battery terminal

Battery charger input fuse blown out

Main supply failure

Question 6 of 28

Question 7 of 28

7. Which is frequency converter?

Rectifiers

Cyclo converters

D.C to A.C converters

D.C choppers

Question 7 of 28

Question 8 of 28

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

Increase the AH capacity of battery

Decrease the AH capacity of battery

Maintain battery terminal voltage always 90% of rating

Increase the VA rating of UPS

Question 8 of 28

Question 9 of 28

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

Current divider network

Resistance temperature detector network

Tapped transformer network

Voltage divider network

Question 9 of 28

Question 10 of 28

10. Which transformer is used in servo voltage stabilizer?

Step down transformer

Constant voltage transformer

Toroidal autotransformer

Step up transformer

Question 10 of 28

Question 11 of 28

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

Buckling

Polarization

Local action

Amalgamation

Question 11 of 28

Question 12 of 28

12. Where square wave inverters are used?

Computers

DVD players

TV receiver

General lighting

Question 12 of 28

Question 13 of 28

13. Which principle the constant voltage transformer works?

Fall in potential principle

Self induction principle

Mutual induction principle

Ferro-resonant principle

Question 13 of 28

Question 14 of 28

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

Geyser

Television

Grinder

Pump motor

Question 14 of 28

Question 15 of 28

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

Rectifier unit

Controller unit

Battery unit

Inverter unit

Question 15 of 28

Question 16 of 28

16. Which is the function of an inverter?

Converts D.C voltage into higher D.C voltage

Converts A.C voltage into D.C voltage

Converts A.C voltage into higher A.C voltage

Converts D.C voltage into A.C voltage

Question 16 of 28

Question 17 of 28

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

Voltmeter

Ammeter

Multimeter

Ohmmeter

Question 17 of 28

Question 18 of 28

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

Oscillator and amplifier stages

Amplifier and transformer output stages

Oscillator and rectifier stages

Oscillator, amplifier and transformer output stages

Question 18 of 28

Question 19 of 28

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

Ferrite core type transformer

Ring core type transformer

Auto transformer

Static transformer

Question 19 of 28

Question 20 of 28

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

Battery is short circuited

Fault in inverter circuit

Mains earthing is not proper

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

Question 20 of 28

Question 21 of 28

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

Decrease

Becomes zero

Remain same

Increase

Question 21 of 28

Question 22 of 28

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

Provide constant current charging

Provide constant potential method charging

Provide trickle charging

Provide freshening charge

Question 22 of 28

Question 23 of 28

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

Manual stepped voltage stabilizer

Servo voltage stabilizer

Constant voltage transformer stabilizer

Automatic voltage stabilizer

Question 23 of 28

Question 24 of 28

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

Oscillator circuit

Amplifier circuit

Rectifier circuit

Feedback circuit

Question 24 of 28

Question 25 of 28

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

Autostat

Over voltage relay

Under voltage relay

Output transformer

Question 25 of 28

Question 26 of 28

26. What is the full form of PWM?

Phase Width Modulation

Pulse Wide Modulation

Phase Wide Modulation

Pulse Width Modulation

Question 26 of 28

Question 27 of 28

27. 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 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?

211 V

233 V

228 V

216 V

Question 28 of 28