Testing And Commissioning Of Electrical Equipment’S Set 11
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This set of Testing and Commissioning of Electrical Equipment’s Multiple Choice Questions & Answers (MCQs) focuses on Testing And Commissioning Of Electrical Equipment’S Set 11
Q1 | Where severe synchronising swing occur, the relay employed is
- Impedance relay
- Mho relay
- Reactance relay
- Induction relay
Q2 | For the protection of lines against faults involving variable fault resistance, thepreferred relaying scheme is a
- Plain impedance relay
- Directional over-current relay
- Mho relay
- Reactance relay
Q3 | For ground fault we prefer
- Plain impedance relay
- Directional over current relay
- Mho relay
- Reactance relay
Q4 | Admittance relay
- Nondirectional relay
- Directional relay
- Differential relay
- None of the above
Q5 | The relay used for feeder protection is
- Under voltage relay
- Translay relay
- Thermal relay
- Buchholz relay
Q6 | Which relay is used to detect and protect internal fault in a transformer ?
- Buchholz relay
- Directional relay
- Thermal relay
- Distance relay
Q7 | Which one of the following relay has the capability of anticipating the possiblemajor fault in a transformer ?
- Over-current relay
- Differential relay
- Buchholz relay
- Over fluxing relay
Q8 | Zero sequence current is used for relaying purpose only in the case of
- Phase over current really
- Phase impedance relay
- Ground over current relay
- Ground impedance relay
Q9 | To prevent mal operation of differentially connected relay while energising atransformer, the relay restraining coil is biased with
- Second harmonic current
- Third harmonic current
- Fifth harmonic current
- Seventh harmonic current
Q10 | How many relays are used to detect interphase fault of a three line system?
- One
- Two
- Three
- Six
Q11 | Which is the main relay for protecting up to 90% of the transmission line-length inthe forward direction?
- Directional over current relay
- Mho relay
- Carrier current protective relay
- Impedance relay
Q12 | For protection of parallel feeders fed from one end, the relays required are
- Nondirectional relays at the source end and directional relay at the load end
- Nondirectional relay at both ends
- Directional relay at source end and nondirectional relay at load end
- Directional relay at both ends
Q13 | Relays can be designed to respond to changes in
- Resistance, reactance or impedance
- Voltage and current
- Light intensity
- All of the above
Q14 | DC shunt relays are made of
- Few turns of thin wire
- Few turns of thick wire
- Many turns of thin wire
- Many turns of thick wire
Q15 | In order that current should flow without causing excessive heating or voltagedrop, the relay contacts should
- Have low contact resistance
- Be clean and smooth
- Be of sufficient size and proper shape
- Have all above properties
Q16 | Interruption of large currents by relay requires
- Arc suppressing blow out coils
- Wide separation of the open contacts
- High speed opening of contacts
- All of the above
Q17 | To protect most of the electrical equipment handling low power, the types of relaysused are
- Thermocouple
- Electronic and bimetallic
- Both A and B
- None of the above
Q18 | ............. Relays are used for phase faults on long line
- Impedance
- Reactance
- Either of the above
- None of the above
Q19 | ........ Relays is preferred for phase fault on short transmission line
- Induction type
- Reactance
- Impedance
- None of the above
Q20 | The under voltage relay can be used for
- Generators
- Bus bars
- Transformers
- All of the above
Q21 | The single phasing relays are used for the protection of
- Single phase motors only
- Two phase motors only
- Two single phase motor running in parallel
- Three phase motors
Q22 | The inverse definite mean time relays are used for over current and earth faultprotection of transformer against
- Heavy loads
- Internal short circuits
- External short circuits
- All of the above
Q23 | In a static over current relay, inverse time characteristics are obtained by
- A transistor amplifier
- An integrating circuit
- A transistor switch
- A differentiating circuit
Q24 | In the case of transmission line protection, over current relay is used
- Only up to 110 KV
- Only up to 220 KV
- Only up to 50 KV
- Only up to 1100 KV
Q25 | Directional over current relays have two exciting coils connected across
- CT secondaries of two different phases
- VT secondaries of two different phases
- CT and VT secondaries of same phases
- CT and VT secondaries of two different phases