Question 1 of 28

1. 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 1 of 28

Question 2 of 28

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

Battery get short circuited

Relay points are joined together

Defective feedback circuit

Input voltage is very high

Question 2 of 28

Question 3 of 28

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

Servo voltage stabilizer

Constant voltage transformer stabilizer

Manual stepped voltage stabilizer

Automatic voltage stabilizer

Question 3 of 28

Question 4 of 28

4. Which is frequency converter?

D.C to A.C converters

Rectifiers

Cyclo converters

D.C choppers

Question 4 of 28

Question 5 of 28

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

Auto transformer

Ring core type transformer

Ferrite core type transformer

Static transformer

Question 5 of 28

Question 6 of 28

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

Fault in inverter circuit

Mains earthing is not proper

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

Battery is short circuited

Question 6 of 28

Question 7 of 28

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

Over voltage relay

Output transformer

Under voltage relay

Autostat

Question 7 of 28

Question 8 of 28

8. What is the full form of UPS?

Uninterrupted Power Supply

Uniform Power Supply

Universal Power Supply

Unregulated Power Supply

Question 8 of 28

Question 9 of 28

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

Decrease

Remain same

Increase

Becomes zero

Question 9 of 28

Question 10 of 28

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

Controller unit

Inverter unit

Battery unit

Rectifier unit

Question 10 of 28

Question 11 of 28

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

Electro plating

Electro chemical equivalent

Electrolysis

Electro copying

Question 11 of 28

Question 12 of 28

12. Where square wave inverters are used?

DVD players

Computers

General lighting

TV receiver

Question 12 of 28

Question 13 of 28

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

Oscillator circuit

Feedback circuit

Amplifier circuit

Rectifier circuit

Question 13 of 28

Question 14 of 28

14. Which transformer is used in servo voltage stabilizer?

Toroidal autotransformer

Constant voltage transformer

Step up transformer

Step down transformer

Question 14 of 28

Question 15 of 28

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

Battery charger input fuse blown out

Incorrect over load settings

Main supply failure

Loose connection in battery terminal

Question 15 of 28

Question 16 of 28

16. Which is the function of an inverter?

Converts A.C voltage into D.C voltage

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

Question 16 of 28

Question 17 of 28

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

Polarization

Amalgamation

Buckling

Local action

Question 17 of 28

Question 18 of 28

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

Provide constant current charging

Provide freshening charge

Provide constant potential method charging

Provide trickle charging

Question 18 of 28

Question 19 of 28

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

Pump motor

Grinder

Geyser

Television

Question 19 of 28

Question 20 of 28

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

Amplifier and transformer output stages

Oscillator and amplifier stages

Oscillator, amplifier and transformer output stages

Oscillator and rectifier stages

Question 20 of 28

Question 21 of 28

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

Voltmeter

Ammeter

Multimeter

Ohmmeter

Question 21 of 28

Question 22 of 28

22. Which principle the constant voltage transformer works?

Mutual induction principle

Self induction principle

Fall in potential principle

Ferro-resonant principle

Question 22 of 28

Question 23 of 28

23. 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 23 of 28

Question 24 of 28

24. What is the full form of PWM?

Pulse Width Modulation

Pulse Wide Modulation

Phase Width Modulation

Phase Wide Modulation

Question 24 of 28

Question 25 of 28

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

Tapped transformer network

Current divider network

Resistance temperature detector network

Voltage divider network

Question 25 of 28

Question 26 of 28

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

1.5 V and 32 AH

6 V and 24 AH

3 V and 16 AH

4.5 V and 8 AH

Question 26 of 28

Question 27 of 28

27. 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 27 of 28

Question 28 of 28

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

Step up AC from amplifier

Step down AC from amplifier

Step down input AC

Step up input AC

Question 28 of 28