Post

Inverter and Ups

Electrician Trade Theory, Module-10

Posted Updated
Preview Image
By Roni
4 min read
Inverter and Ups


⭕️ Show all Answers


Q1: What is the minimum permissible single phase working voltage, if the declared voltage is 240V as per ISI?

  • 233 V
  • 228 V
  • 216 V
  • 211 V
Show Calculation 240V-5% = 228V

Q2: Which term refers that the mass of a substance liberated from an electrolyte by one coulomb of electricity?

  • Electrolysis
  • Electro plating
  • Electro copying
  • Electro chemical equivalent

Q3: What is the full form of UPS?

  • Uniform Power Supply
  • Universal Power Supply
  • Unregulated Power Supply
  • Uninterrupted Power Supply

Q4: Which is frequency converter?

  • Rectifiers
  • D.C choppers
  • Cyclo converters
  • D.C to A.C converters

Q5: What is the full form of PWM?

  • Pulse Wide Modulation
  • Pulse Width Modulation
  • Phase Wide Modulation
  • Phase Width Modulation

Q6: What is the advantage of on-line UPS over offline UPS?

  • Supplies constant power output
  • It gives constant output frequency
  • Works on single phase or three phase supply
  • Free from change over and transition problems

Q7: Which electronic circuit is used in a automatic voltage stabilizer to produce constant output voltage?

  • Rectifier circuit
  • Amplifier circuit
  • Oscillator circuit
  • Feedback circuit

Q8: Which feedback network is used for automatic voltage stabilizer?

  • Current divider network
  • Voltage divider network
  • Tapped transformer network
  • Resistance temperature detector network

Q9: Which electrical device is actuating the voltages in a stepped voltage stabilizer?

  • Autostat
  • Output transformer
  • Over voltage relay
  • Under voltage relay

Q10: What is the effect in internal resistance of a discharged cell?

  • Increase
  • Decrease
  • Becomes zero
  • Remain same

Q11: Calculate the voltage and ampere/hour, if four cells rated as 1.5 V and 8 AH are in parallel?

  • 6 V and 24 AH
  • 3 V and 16 AH
  • 4.5 V and 8 AH
  • 1.5 V and 32 AH

Q12: Which is the application of automatic stepped voltage stabilizer?

  • Geyser
  • Grinder
  • Television
  • Pump motor

Q13: 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

Q14: What is the purpose of output transformer in inverters?

  • Step up input AC
  • Step down input AC
  • Step up AC from amplifier
  • Step down AC from amplifier

Q15: Which type of output transformer is used in automatic voltage stabilizer?

  • Auto transformer
  • Static transformer
  • Ring core type transformer
  • Ferrite core type transformer

Q16: Which principle the constant voltage transformer works?

  • Self induction principle
  • Fall in potential principle
  • Ferro-resonant principle
  • Mutual induction principle

Q17: Which transformer is used in servo voltage stabilizer?

  • Step up transformer
  • Step down transformer
  • Torodial autotransformer
  • Constant voltage transformer

Q18: What is the type of A.C voltage stabilizer?

A.C voltage stabilizer type

  • Servo voltage stabilizer
  • Automatic voltage stabilizer
  • Manual stepped voltage stabilizer
  • Constant voltage transformer stabilizer

Q19: Which instrument is used to check short circuit faults in electronic circuit in voltage stabilizer?

  • Ammeter
  • Voltmeter
  • Ohmmeter
  • Multimeter

Q20: What are the important stages in a simple inverter?

  • Oscillator and rectifier stages
  • Oscillator and amplifier stages
  • Amplifier and transformer output stages
  • Oscillator, amplifier and transformer output stages

Q21: Where square wave inverters are used?

  • Computers
  • TV receiver
  • DVD players
  • General lighting

Q22: How the backup time of UPS can be increased?

  • Increase the VA rating of UPS
  • Increase the AH capacity of battery
  • Decrease the AH capacity of battery
  • Maintain battery terminal voltage always 90% of rating

Q23: How the hard sulphation defect in secondary cell can be prevented?

  • Provide trickle charging
  • Provide freshening charge
  • Provide constant current charging
  • Provide constant potential method charging

Q24: Which part in UPS supplies continuous output voltage in case of input voltage failure?

  • Battery unit
  • Inverter unit
  • Rectifier unit
  • Controller unit

Q25: What is the effect during loading of the cell, the current strength falls and become zero?

  • Buckling
  • Polarization
  • Local action
  • Amalgamation

Q26: What is the reason for having low back up time in UPS?

  • Fault in inverter circuit
  • Battery is short circuited
  • Mains earthing is not proper
  • Ampere hour (A.H) capacity of battery is not sufficient

Q27: Which is the cause for the fault if the output voltage of UPS is higher than normal?

  • Battery get short circuited
  • Defective feedback circuit
  • Input voltage is very high
  • Relay points are joined together

Q28: 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
Found a mistake or mismatch in the question or answer? Let us know via email.
2nd year, Trade Theory
Theory ITI
This post is licensed under CC BY 4.0 by the author.