Objective Questions on Inverters & UPS for Electrician Trade
| Sr. No. | Questions with options |
| 1 | What is the minimum permissible single phase working voltage, if the declared voltage is 240 V as per ISI?
(a) 233 V (b) 228 V (c) 216 V (d) 211 V Ans – (b) |
| 2 | Which term refers that the mass of a substance liberated from an electrolyte by one coloumb of electricity?
(a) Electrolysis (b) Electro plating (c) Electro copying (d) Electro chemical equivalent Ans – (d) |
| 3 | What is the full form of abbreviation UPS?
(a) Uniform Power Supply (b) Universal Power Supply (c) Unregulated Power Supply (d) Uninterrupted Power Supply Ans – (d) |
| 4 | Which is frequency converter?
(a) Rectifiers (b) D.C choppers (c) Cyclo converters (d) D.C to A.C converters Ans – (c) |
| 5 | What is the full form of PWM?
(a) Pulse Wide Modulation (b) Pulse Width Modulation (c) Phase Wide Modulation (d) Phase Width Modulation Ans – (b) |
| 6 | What is the advantage of on-line UPS over offline UPS?
(a) Supplies constant power output (b) It gives constant output frequency (c) Works on single phase or three phase supply (d) Free from change over and transition problems Ans – (d) |
| 7 | Which electronic circuit is used in a automatic voltage stabilizer to produce constant output voltage?
(a) Rectifier circuit (b) Amplifier circuit (c) Oscillator circuit (d) Feedback circuit Ans –(d) |
| 8 | Which feedback network is used for automatic voltage stabilizer?
(a) Current divider network (b) Voltage divider network (c) Tapped transformer network (d) Resistance temperature detector network Ans –(b) |
| 9 | Which electrical device is actuating the voltage in a stepped voltage stabilizer?
(a) Autostat (b) Output transformer (c) Over voltage relay (d) Under voltage relay Ans – (a) |
| 10 | What is the effect in internal resistance of a discharged cell?
(a) Increase (b) Decrease (c) Becomes zero (d) Remain same Ans – (a) |
| 11 | Calculate the voltage and ampere/hour, if four cells rated as 1.5 V and 8 A.H are in parallel?
(a) 6 V and 24 AH (b) 3 V and 16 AH (c) 4.5 V and 8 AH (d) 1.5 V and 32 AH Ans – (d) |
| 12 | Which is the application of automatic stepped voltage stabilizer?
(a) Geyser (b) Grinder (c) Television (d) Pump motor Ans – (c) |
| 13 | Which is the function of an inverter?
(a) Converts A.C voltage into D.C voltage (b) Converts D.C voltage into A.C voltage (c) Converts D.C voltage into higher D.C voltage (d) Converts A.C voltage into higher A.C voltage Ans – (b) |
| 14 | What is the purpose of output transformer in inverters?
(a) Step up input AC (b) Step down input AC (c) Step up AC from amplifier (d) Step down AC from amplifier Ans – (c) |
| 15 | Which type of output transformer is used in automatic voltage stabilizer?
(a) Auto transformer (b) Static transformer (c) Ring core type transformer (d) Ferrite core type transformer Ans – (a) |
| 16 | Which principle the constant voltage transformer works?
(a) Self-induction principle (b) Fall in potential principle (c) Ferro-resonant principle (d) Mutual induction principle Ans – (c) |
| 17 | Which transformer is used in servo voltage stabilizer?
(a) Step up transformer (b) Step down transformer (c) Torodial auto transformer (d) Constant voltage transformer Ans – (c) |
| 18 | Which instrument is used to check short circuit faults in electronic circuit in voltage stabilizer?
(a) Ammeter (b) Voltmeter (c) Ohmmeter (d) Multimeter Ans –(d) |
| 19 | What are the important stages in a simple inverter?
(a) Oscillator and rectifier stages (b) Oscillator and amplifier stages (c) Amplifier and transformer output stages (d) Oscillator, amplifier and transformer output stages Ans – (d) |
| 20 | Where square wave inverters are used?
(a) Computers (b) TV receiver (c) DVD players (d) General lighting Ans –(d) |
| Published On – 12th June 2022 | |
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