OBJECTIVE –QUESTIONS ON TRD (PART - 9 )

OBJECTIVE –QUESTIONS ON TRD (PART - 9 )

501. 25KV CB/BM locks out due to low air pressure at ----------------------

502. In a 25KV CB/BM air pressure is maintained by ------------------------- a) Compressor b) Air pressure limit switch c) Safety valve d) TPC

503. In 25KV CB/BM, ---------------------- is used for safety of Air Cylinder.

504. ----------°C is taken as Standard for determination of Gas Pressure in 25KV CB/BM.

505. Only a competent railway servant can operate the 25KV Isolator switch. (True/False)

506. Operation of 25KV Isolator switch is permitted to all railway servants. (True/False)

507. In open state ,the clearance between fix and moving contact of an 25KV Isolator should be 500mm. (True/False)

508. In open state ,the clearance between fix and moving contact of an 132KV Isolator should be more than 500mm. (True/False)

509. On-Load operation of an 25 KV isolator switch should not be done. (True/False)

510. An elementary section can be isolated by isolator switch. (True/False)

 511. Nitorgen Gas is filled in the pole unit of Vacuum type CB. (True/False)

512. Any type of Gas or Air is not filled in the pole unit of Vacuum type CB/BM, (True/False)

 513. Total Break time of 25KV single pole SF6 Circuit Breaker should not be more than 65 milli-seconds. (True/False)

514. Total Break time of 25KV single pole SF6 BM should not be more than 80 Mili-seconds. (True/False)

515. In no condition SF6 gas can convert into liquid state. (True/False)

516. At some specific high pressure and low temperature, SF6 gas converts into liquid state. (True/False)

517. PTW must be obtained from TPC for the maintenance of CB/BM. (True/False)

518. It is safe to keep the CB/BM on local control while its maintenance is in progress. (True/False)

519. It is safe to switch off 110 volt DC supply of CB/BM while its maintenance is in progress. (True/False)

520. Gas density switch generates alarm according to gas pressure in the pole unit. (True/False)

521. It is impossible to check the settings of gas density switch. (True/False)

522. Combined earth pit resistance of a TSS should not be more than ------------- Ω.

523. Combined earth pit resistance of a SSP should not be more than ------------- Ω.

524. Combined earth pit resistance of a SP should not be more than ------------- Ω.

525. Single earth-pit resistance should not be more than -------------------.

526. The ideal value of EPR would be ------------------.

527. As per ACTM, earth electrodes should be ------------- meters long.

528. As per ACTM, bore of earth electrodes should be ----------- cm.

529. As per ACTM, minimum separation between two earth pits is -----------------.

530. Treatment by mixture of salt-charcoal should be done if the EPR is less than 10Ω. (true/false)

531. Treatment by mixture of salt-charcoal should be done if the EPR is more than 10Ω. (true/false)

532. It is good to pour water in earth pit at a regular interval. (true/false)

533. Over a year, EPR should be checked during dry and hot season. (true/false)

534. In a switching station, all earth electrodes are connected in ----------- connection. (series/parallel)

535. Earth pit for remote control equipment should not be connected with earth pits/ earth grid of switching station. (true/false)

536. Earthing for RCE should not be connected with earthing of switching ,becausea) Traction current may harm to RCE equipments. b) RCE equipments work on DC supply. c) There is no such restriction.

537. LA rating for 25KV system is -------------------------.

538. LA rating for 110KV system is -------------------------.

539. LA rating for 132KV system is -------------------------.

540. LA rating for 220KV system is -------------------------.

541. The abnormal conditions ,LA protects from, is --- a) Short circuit b) Open circuit c) Low voltage d) Voltage surge.

542. LA may be tested from Megger. (true/false)

543. Prior to erection, LA should be tested from ------------------.

544. POH of LA should be done after 4 years. (true/false)

545. There is no POH schedule for LA. (true/false)

546. 42KV LA should be Meggered by 500 volt megger. (true/false)

547. Megger value for 42KV LA should be? (2500MΩ , 1GΩ , 10GΩ, 200KΩ)

548. Megger value for 198KV LA should be? (2500MΩ , 1GΩ , 10GΩ, 200KΩ)

549. LA is connected between line and earth. (True / False)

550. In three phase system (132 KV) , LA is connected between any two phases. (True / False)

551.	Within a TSS, the minimum height of 25KV bus-bar from ground level is ------------				.
552.	Control circuits for switching stations works on			---------------------- volts DC.
553.	In a TSS, voltage ratio of 100KVA AT is ---
	a) 100KV /230 volt	b) 100KV/440 volt
	c) 25KV/230 volt	d) 25KV/ 440volt.
554.	Electrical Clearance for 25KV system is --------------------------			.
555.	Catenary indication is a must for Closing Operation of ------------------------
	a) Doors of control penal of TSS.			b) Sectioning BM of SSP
	c) HV CB			d) Bridging BM.
556.	At voltage ,lesser than 19 KV –
	a) Bridging BM gets open, if already closed.
	b) Air compressor of CB gets stop.		c) HV/LV CB trips d) Non of the above

557.On a SSP over lap, which side of OHE gets parallel by the paralleling BM of that SSP?

a) TSS

b) SP

c) middle

d) both side

558.Bus –bar connection gets bad in colour, what it indicates for?

a)Bus Bar is getting hot due to bad connection.

b)Connection is alright and bus bar do not getting hot.

c)General climatic effect on bus-bar.

d)Poor quality of bus- bar material.

559.Bus-bar connection should be opened, cleaned and retighten if -

a) CB trips on WTI indication.	b) Pre-monsoon is being done.
c) Bus –bar is bad in colour.	d) Non of the above.

560. To deduce average PF of a TSS over a month, what items of meter reading of that

		TSS for the month shall be used?
		a) KVAH, KVARH	b) KVAH, KWH
	c) KVA, KVAR		d) KVA, KW.
561.	What is meant from Earth-Screen, in context of a TSS?
	a) Under Ground earth-grid.		b) Earthed fencing around TSS.
	c) A caution –board.		d) Earth wire hanging on TSS gantry.
562.	Under voltage relay is related with –
	a) All BM of TSS		b) Paralleling BM of SP and SSP.
	c) Sectioning BM of SSP		d) Bridging BM of SP.

563.A lair of ballast, used in switch-yard, serves as insulation. (True/False)

564.In a Traction Transformer ,Bushing CT is used for –

a) OCR

b) DPR

c) EFR

d) DFR

565.For a 132KV/25kV traction transformer, how many CT are required to Differential Protection?

a) 2 No LV taret CT	b) 2No. HV taret CT
c) HV Gantry-CT, LV taret CT	d) HV and LV taret CT
566. Differential protection works against which type of fault?
a) Internal faults	b) Over voltage
c) Over current	d) Low oil level.

567.OCR –T is protection from?

a)Sustained over Currents due to over load.

b)Sudden rise of current due to earth fault.

c)Over current due to earth fault away from TSS.

d)Sudden rise of current by 200% of normal current due to any reason.

568.DPR is Protection from?

a)Sustained over Currents due to over load.

b)Sudden rise of current due to earth fault.

c)Earth fault away from TSS.

d)Sudden rise of current by 200% of normal current due to any reason.

569.Which relay gets its input from both the CT and PT?

a) OCR

b) DPR

c) EFR

d) DFR

570.Delta-I relay is said as back-up to DPR. (True/False)

571.Every type of CB is having the facility to alter the setting of its tripping current.(true/false)

572.What would you do, if you want to change the tripping current of a CB?

a)It might not be done; the CB would have been replaced.

b)CT would have been replaced.

c)Relay setting should be adjusted.

d)Battery voltage should be changed.

573.WPC relay is placed in SP. (true/false)

574.WPC relay is placed in TSS. (true/false)

575.What is correct about WPC relay?

	a) One No in SP	b) two No. in SP	c) one No. in TSS	d) two No. in TSS
576.	Earth –Screen is a protection against –
	a) Touch Voltage	b) Step Voltage	c) Lightening Stroke	d) Earth Fault.
577.	CTD is an interlock arrangement –
	a) It is a false statement		b) CB tripping and 110 volt DC supply
	c) CB tripping and auto recloser.		d) High voltage and alarm.

578.OCR-I is a protection against -

a)Sustained over Currents due to over load.

b)Sudden rise of current due to earth fault.

c)Over current due to earth fault away from TSS.

d)Sudden rise of current by 200% of normal current due to any reason.

579.ITR is a fault sensing relay. (true/false)

580.ITR is a auxiliary relay for transformer protection. (true/false)

581.It is not the auto –reset type relay-

	a) OCR	b) DPR	c) WPC	d) ITR
582.	Is it necessary to check the transformer before putting on load if it was out from
	circuit due to Differential relay? (Yes/No)
583.	Voltage ratio of PT type I ----------------------------------			.
584.	Voltage ratio of PT type II ----------------------------------			.
585.	KVA rating of AT normally used for CLS is ------------------------------				.
586.	Voltage ration of AT normally used for CLS is ----------------------------				.
587.	Rating of AT normally used in SP/SSP is		--------------------------------		KVA
588.	-------------No of AT is used in TSS. ( 1, 2, 3, 4)
589.	100KVA AT of TSS is used for-
	a) Yard Lighting		b) Stand by
	c) Filtration Plant		d) Power Factor correction.
590.	Rating of PT normally used for catenary indication is -----------------------------				.
591.	DO fuse rating for 10 KVA AT is ----------------------------------			.
592.	Rating of KIT- KAT fuse for 10KVA AT is -----------------------------------				.
593.	Minimum permissible Megger value between HT- E for a CT is --------------------				MΩ
594.	Minimum permissible Megger value between LT- E for a CT is --------------------				MΩ
595.	Minimum permissible Megger value between HT- LT for a CT is -------------------				MΩ
596.	Minimum permissible Megger value between HT- E for a PT is --------------------				MΩ
597.	Minimum permissible Megger value between LT- E for a PT is --------------------				MΩ
598.	Minimum permissible Megger value between HT- LT for a PT is -------------------				MΩ
599.	Minimum permissible Megger value between HT- E for a AT is --------------------				MΩ
600.	Minimum permissible Megger value between LT- E for a AT is --------------------				MΩ
601.	Minimum permissible Megger value between HT- LT for a AT is -------------------				MΩ
602.	In case of CT, number of turns in primary is -------			than number of turns in secondary.
603.	In case of PT number of turns in primary is -------			than number of turns in secondary.
604.	The secondary winding of a CT should not be open circuited if primary is charged-
	a) There is no such restriction.		b) Primary becomes Over-Voltage
	c) CT winding will burn –out.		d) CB can not be closed
605.	Most suited place for cable storage is –
	a) Moist and Dark		b) Moist and Sun light
	c) Dry and dark		d) Dry and Sun light.
606.	What is used to indicate the position of under ground cable?----------------------
607.	Cable laying should be done in cable trenches ;due to
	a) Ease of maintenance.			b) Mechanical protection
	c) Eases of identification during maintenance.			d) all of the above.

608.While storing cables ,its ends should be properly covered by something like plastic etc.-

a) It is of no use.	b) Such action is wrong.
c) It must be done.	e) It is sufficient to cover only one end.

609.To protect the cable from the effects of moisture its free ends should be covered by something like plastic etc. (true/false)

610.What you understand about size of a cable if it is said 70 Sq mm two core cable-

a)Cross sectional area of the cable is 70 sq mm.

b)Size of each core is 70 sq mm

c)Size of one core is 35 sq mm

d)Cable is to be used for CLS purposes.

611.There is a fuse in the secondary of the CT. ( true/false)

612.There is a fuse in the secondary of the PT. ( true/false)

613.Some times ,there is only secondary winding in CT. (true/false)

614.DO fuse is protection for ---------------------------------. (OHE , AT)

615.Can DO-fuse be used for protection of CT. (Yes/ No)

616.230 volt AT winding should be meggered from 500 volt megger. (true/false)

617.Size means length of the cable used for.( true/ false).

618.Armor is meant for mechanical protection of the cable.(true/false)

619.Cable size of discharge –rod used in 25KV OHE is –

	a) Multi-core 40 sq. mm		b) Single Core 40 sq. mm
	c) Multi-core 20 sq. mm		d) Single Core 20 sq. mm
620.	To crimp a lug properly on the cable core, how many strands are permitted to cut?
	a) 0	b) 1	c) 2	d) 3
621.	The insulation resistance of a cable depends on –
	a) Condition of insulation		b) length
	c) Thickness of insulation		d) all of the above.
622.	Hand tool used to put the lug on cable core tightly is –
	a) Torque Rinch		b) Ring Spanner	c) Crimping tool	d) LN key

ANSWER

501. 12 Kg/cm²               502. b                        503. Safety Valve           504. 20

 505. True 506. False 507. True 508. True 

509. True 510. True 511. False 512. True 

513. True  514. True 515. False 516. True 

517. True 518. True 519. True 520. True 

521. False 522. 0.5Ω 523. 2.0Ω 524. 2.0Ω

 525. 10.0Ω 526. 0 527. 4 528. 4 

529. 6 530. False 531. True 532. True 

533. True    534. Parallel 535. True 536. a 

537. 42kv 538. 98kv 539. 120kv 540. 198kv 

541. d 542. True  543. Megger 544. False 

545. True 546. False 547. 1GΩ 548. 10GΩ 549. True 550. False

551. 3.80 mts             552.110              553.c            554.a                      555.d             556.a

557.b                         558.a                  559.c            560.d                      561.d              562.d

563.True                    564.d                   565.d          566.a                      567.a              568.c
  

569.b                          570.True            571.False        572.c                 573.False          574.True

575.d

576.c

577.b

578.d                        579.False

580.True

581.d

582.Yes

583.25kv/100 volts

584.25kv/110 volts

585.10

586.25kv/230 volts

587.10

588.2

589.c

590.25kv/100 volts

591.1 amp.

592.63 amp

593.200 MΩ

594.2 MΩ

595.200 MΩ

596.200 MΩ

597.2 MΩ

598.200 MΩ

599.200 MΩ

600.2 MΩ

601.200 MΩ

602.Less

603.More

604.c

605.c

606.Route Indicter/ Cable Marker

607.d

608.c

609.True

610.b

611.False

612.True

613.True

614.AT

615.NO

616.True

617.False

618.True

619.b

620.a

621.d

622.c

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