Question 1 of 28

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

Inverter unit

Battery unit

Controller unit

Rectifier unit

Question 1 of 28

Question 2 of 28

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

Output transformer

Over voltage relay

Autostat

Under voltage relay

Question 2 of 28

Question 3 of 28

3. What is the full form of UPS?

Unregulated Power Supply

Uninterrupted Power Supply

Universal Power Supply

Uniform Power Supply

Question 3 of 28

Question 4 of 28

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

Electrolysis

Electro copying

Electro plating

Electro chemical equivalent

Question 4 of 28

Question 5 of 28

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

Maintain battery terminal voltage always 90% of rating

Increase the VA rating of UPS

Decrease the AH capacity of battery

Increase the AH capacity of battery

Question 5 of 28

Question 6 of 28

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

Input voltage is very high

Relay points are joined together

Defective feedback circuit

Battery get short circuited

Question 6 of 28

Question 7 of 28

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

Increase

Decrease

Becomes zero

Remain same

Question 7 of 28

Question 8 of 28

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

Grinder

Geyser

Pump motor

Television

Question 8 of 28

Question 9 of 28

9. Which is frequency converter?

D.C to A.C converters

D.C choppers

Cyclo converters

Rectifiers

Question 9 of 28

Question 10 of 28

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

Static transformer

Auto transformer

Ring core type transformer

Ferrite core type transformer

Question 10 of 28

Question 11 of 28

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

Step down input AC

Step down AC from amplifier

Step up input AC

Step up AC from amplifier

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 feedback network is used for automatic voltage stabilizer?

Tapped transformer network

Voltage divider network

Resistance temperature detector network

Current divider network

Question 13 of 28

Question 14 of 28

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

Ammeter

Voltmeter

Multimeter

Ohmmeter

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

Main supply failure

Incorrect over load settings

Loose connection in battery terminal

Question 15 of 28

Question 16 of 28

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

Works on single phase or three phase supply

It gives constant output frequency

Free from change over and transition problems

Supplies constant power output

Question 16 of 28

Question 17 of 28

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

228 V

211 V

233 V

216 V

Question 17 of 28

Question 18 of 28

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

Oscillator and rectifier stages

Amplifier and transformer output stages

Oscillator and amplifier stages

Oscillator, amplifier and transformer output stages

Question 18 of 28

Question 19 of 28

19. Which principle the constant voltage transformer works?

Self induction principle

Mutual induction principle

Ferro-resonant principle

Fall in potential principle

Question 19 of 28

Question 20 of 28

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

Manual stepped voltage stabilizer

Automatic voltage stabilizer

Constant voltage transformer stabilizer

Servo voltage stabilizer

Question 20 of 28

Question 21 of 28

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

Provide freshening charge

Provide trickle charging

Provide constant potential method charging

Provide constant current charging

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?

6 V and 24 AH

1.5 V and 32 AH

4.5 V and 8 AH

3 V and 16 AH

Question 22 of 28

Question 23 of 28

23. Which is the function of an inverter?

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

Converts D.C voltage into higher D.C voltage

Question 23 of 28

Question 24 of 28

24. 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 24 of 28

Question 25 of 28

25. What is the full form of PWM?

Pulse Wide Modulation

Phase Wide Modulation

Phase Width Modulation

Pulse Width Modulation

Question 25 of 28

Question 26 of 28

26. Which transformer is used in servo voltage stabilizer?

Step down transformer

Constant voltage transformer

Toroidal autotransformer

Step up transformer

Question 26 of 28

Question 27 of 28

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

Polarization

Amalgamation

Buckling

Local action

Question 27 of 28

Question 28 of 28

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

Oscillator circuit

Amplifier circuit

Feedback circuit

Rectifier circuit

Question 28 of 28