OBJECTIVE –QUESTIONS ON TRD (PART - 7 )
351. The voltage increases and the capacity remain constant, if the cells are connected in parallel. (True/ False)
352. The capacity of cell increases with increase of its size. (True/ False)
353. The Voltage increases with increase of the size of cell. (True/ False)
354. To connect positive terminal with the positive one, shall be a parallel connection. (True/ False)
355. To connect positive terminal with a negative one, shall be a parallel connection. (True/ False)
356. To prepare the electrolyte, acid shall be poured into distilled water. (True/ False)
358. For each degree rise of temperature above 27°C, the hydrometer reading should be added with 0.0007. (True/ False)
359. The hydrometer reading should be deducted with 0.0007 for each degree rise of temperature above 27°C (True/ False)
360. The hydrometer reading should be added with 0.0007 for each degree fall of temperature below 27°C. (True/ False)
361. The hydrometer reading should be deducted with 0.0007 for each degree fall of temperature below 27°C. (True/ False)
362. The gas emerging from a battery may cause explosion. (True/ False)
363. The orifice at the top of vent plug should normally be open, but should be closed during boost charging. ( True/False)
364. The orifice at the top of vent plug should normally be closed. ( True/False)
365. The orifice at the top of vent plug should normally be open. ( True/False)
366. Unit of specific gravity is gram per cubic centimeter. ( True/False)
367. Specific gravity has no unit. ( True/False)
368. Battery rating for TSS is 200AH. ( True/False)
369. Battery rating for SP, SSP is 40AH. ( True/False)
370. Battery rating for all switching stations has been standardized as200AH. ( True/False)
371. Normally battery with higher AH capacity sizes bigger. ( True/False)
372. Cell voltage of lead-acid cell does not depend on its size. ( True/False)
373. Hydrometer is used for measurement of SPG. ( True/False)
374. The unit of Transformer capacity is -------------------------.
375. How many numbers of winding are there in a single phase transformer? (Two, One)
376. Healthy silica gels colors is ------------ ( Pink / Blue )
377. Silica Gel turns ------------------ (colour) absorbing moisture.
378. BDV of Transformer oil should be ----------------------- KV.
379. Colour of New transformer oil is --------------------------------.
380. -------------------- is fixed between Bell Tank and Conservator tank. ( Buchholtz relay/ Breather)
381. The transformer oil should be replaced if it turns-----------------------(colour)
382. What is the use of transformer oil? a) Insulation b) Cooling c) Both the above.
383. Transformer Oil is categorized as? a) Edible oil b) Fuel c) Insulating oil
384. Which device is used to protect the transformer from excessive internal pressure? a) PRD b) Buchholtz Relay c) MOLG d) Drain Cork.
385. -------------- is used for low oil level protection.
386. What is used for cooling of a transformer? a) Conservator tank b) Radiator c) Breather d) Core
387. The power loss that occurs in transformer winding is called as------------------.
388. The power loss that occurs in transformer core is called as------------------.
389. The ratio of rated voltage of primary and secondary winding of a transformer is called as -----------------------------. 390. For a transformer, the product of primary side voltage and current is equal to product of secondary side voltage and ---------------.
391. ----------- is the unit to express moisture content in transformer oil.
392. POH of Power Transformer is done after ----------------.years.
393. Insulation Resistance between LV and E at 30°C for a 132KV / 25KV transformer should not be less than-----------------------.
394. Insulation Resistance between HV and E at 30°C for a 132KV / 25KV transformer should not be less than-----------------------.
395. Insulation Resistance between LV and HV at 30°C for a 132KV / 25KV transformer should not be less than-----------------------.
396. Traction Transformer can be run for ------------------ minutes at 50% over load.
397. Traction Transformer can be run for 15 minutes at --------------% over load. 398. Traction Transformer can be run for ------------------ minutes at 100% over load.
399. Traction Transformer can be run for 5 minutes at --------------% over load.
400. Setting for oil temperature alarm is -------------°C.
ANSWER – OBJECTIVE QUESTION ON TRD
351. False 352. True 353. False 354. True 355. False 356. True 357. False 358. True 359. False 360. False 361. True 362. True 363. False 364. False 365. True 366. False 367. True 368. True 369. True 370. False 371. True 372. True 373. True 374. Volt-Amperes 375. Two 376. Blue 377. Pink 378. 60 379. Clear transparent 380. Buchholtz relay 381. Black 382. c 383. c 384. a 385. MOLG 386. b 387. Copper loss 388. Iron loss 389. Voltage ratio( Transformation ratio) 390. Secondary side current 391. ppm 392. 10 393. 400MΩ 394. 2000 MΩ 395. 2500 MΩ 396. 15 397. 50 398. 5 399. 100 400. 80
401. Setting for oil temperature trip is -------------°C.
402. Setting for winding temperature alarm is -------------°C.
403. Setting for winding temperature trip is -------------°C.
404. Traction Transformer is normally equipped with ----------------------- tap changer. (On load / off load)
405. The ratio of number of turns in primary and secondary winding of a transformer is called as ----------------------------------------.
406. Transformer Oil is dangerous since it is ---------------------------. a) Inflammable b) Toxic c) Hygroscopic d) Unnatural.
407. Out of the following relations , what would be incorrect for a transformer where N indicates number of turns, V voltage and I current.
408. ONAN / ONAF are the types of – a) Transformer cooling system. b) Winding c) Tap Changer d) Earthing
409. What it indicates, if the terminal connection of a transformer appear bad in colour. a) Abnormal heating of terminals due to loose connection b) Transformer Over load c) Higher EPR. d) Non of the above.
410. Transformer oil sample Crackles on heating ; it is an indication of – a) Increased acid content. b) Too cold sample c) Excessive Water content d) Improved BDV .
411. Oil temperature trip facility is given since at higher temperaturesa) Transformer oil becomes thick and immovable. b) Insulating properties of insulations impair sharply. c) Buchholtz relay trips. d) It becomes difficult to operate tap changer due thicken transformer oil.
412. What is incorrect in context of Buchholtz Relay? a) It is an electromechanical relay. b) It protects transformer from internal faults. c) It requires collection of gas to operate. d) It is situated between bell tank and conservator tank.
413. In case of transformer bushing ,the value of tan-δ testing should not be more than -----
414. In case of transformer bushing ,the value of capacitance should not be more than ---%
415. During maintenance, it is found that oil level in OIP Condenser bushing is low from the set value what action should be taken? a) Transformer can be taken on load. b) Bushing shall be replaced. c) On lowest tap transformer can be taken on load. d) Tan-δ and Capacitance test shall be done and action shall be taken according to results.
416. No need to reset OTI/WTI during ---------------------- scheduled maintenance. a) Monthly b) Half Yearly c) Yearly d) Non of the above.
417. OTI indicates? a) Average temperature of transformer oil. b) Maximum temperature of transformer oil. c) Minimum Temperature of Transformer oil d) Maximum permissible temperature of transformer oil
418. WTI indicates? a) Average Temperature of transformer winding. b) Maximum temperature of transformer winding. c) Minimum temperature of transformer winding. d) Maximum permissible temperature of transformer winding.
419. According to TI/MI -38 what action shall not necessarily be done during monthly maintenance? a) EPR testing b) Inspection of Slica gel breather. c) Check OTI/WTI d) To check bus bar connection for bad –colour.
420. Which Instrument is used for PI checking? a) Ammeter , Voltmeter , Watt meter b) Earth Tester c) Megger d) BDV Tester.
421. Winding is said in good health ,if the value of Polarization Index isa) Less than 1 b) More than 2 c) Value of Polarization Index does not indicate winding condition. d) More than 1, less than 2.
422. Unit for measurement of Polarization Index. a) Volt per second b) Mega –Ohms per second c) Volt per rotation d) there is no unit.
423. During half yearly maintenance ,oil sample for BDV test should be taken – a) Just after shutting down the transformer. b) After cooling of transformer oil. c) After keeping the transformer at 5 No. Tap for half an hour. d) Sample bottle should be filled by taking small quantities over a considerable time during the maintenance.
424. The symbols R60/R10 and R600/R60 bear the relation with ------------- . a) BDV b) PPM c) tan-δ d) Polarization Index.
425. What does it mean by R60/R10 in relation with PI? a) Resistance of 60Ω and 10Ω. b) Megger readings after 10 sec. and 60 sec. respectively . c) Megger readings after 10 sec. and 60 sec when rotation of handle has been stopped. d) Non of the above.
426. According to TI/MI 38, what action should be taken if the value of PI test is less than 1.1 . a) Replace transformer oil. b) Transformer is in good condition. c) Oil filtration and again PI test. d) TI/MI38 do not say any thing about PI test.
427. Which test is not performed on transformer oil? a) IR b) DGA c) BDV d) PPM
428. DGA testing is a test of dissolved ------------------ in transformer oil.
429. ---------------- Test is done to test Electrical Strength of transformer oil. a) IR b) DGA c) BDV d) PPM
430. Which test should be done to know water quantity present in oil sample? a) Crackle Test b) PPM c) Colour Test d) Tan-δ Test.
431. Crackle Test is done to deduce the water quantity in oil sample.( True/false)
432. Factor that affects insulation resistance? a) Size of winding b) Temperature c) Moisture d) All of the above.
433. While meggering a transformer ,------------------------ temperature should also be recorded along with the megger reading. a) Air b) MOLG c) OTI d) a & c
434. While meggering ,what should also be recorded on the test record along with megger reading? a) Megger Rating. b) Make & Serial Number c) Air & OTI d) All of the above.
435. To megger Traction Transformer 500 volt megger is suitable. (True /False)
436. What is incorrect about Oil filtration? a) Initially IR falls with rise of temperature. b) With filtering out dirt and moisture BDV improves. c) Oil filtration do not permits dissolved gases to escape out from oil. d) IR value increases with fall of oil temperature when filtration plant is shut-off.
437. Which test shall not be done for OIP condenser bushing during yearly maintenance? a) tan-δ b) Capacitance c) IR d) Crackle
438. Generally spark gap for 25KV bushing of traction transformer is a) 16.5 cm b) 25 cm c) 75 cm d) 1mt.
439. On selection of higher taps of a tap-changer voltage increases sincea) No. of turns in winding increases. b) Winding resistance reduces. c) Insulation resistance of winding reduces d) Incoming voltage to winding increases.
440. Electrode gap of BDV tester is -----------------mm.
441. Bushing CT is associated with? a) Power Transformer b) AT- 100KVA c) AT at SP d) Feeder CB
442. Bushing CT is provided with all bushings of a power transformer. (True / False)
443. Location of PRD? a) Behind control panel b) below marshaling box c) Above bell tank d) beside conservator tank.
444. Is it true that in the course of usage, acid forms naturally in transformer oil? (Yes/No)
445. Is transformer oil a inflammable liquid? ( Yes/ No)
446. Capacity of a transformer is expressed in KW. (True/False)
447. Buchholtz relay is oil pressure relay. (true/false)
448. Transformer capacity is expressed in KVA.(true/false)
449. BDV value of transformer oil should not be less than 60KV.(true/false)
450. BDV value of transformer oil should not be more than 60KV.(true/false)
ANSWER
401. 85 402. 90 403. 95 404. off load 405. Turn Ratio (Transformation Ratio) 406. a 407. c 408. a 409. a 410. c 411. b 412. a 413. 0.007 414. 110 415. d 416. d 417. b 418. b 419. a 420. c 421. b 422. d 423. a 424. d 425. b 426. c 427. a 428. gases 429. c 430. b 431. false 432. d 433. c 434. d 435. False 436. c 437. d 438. b 439. a 440. 2.5 441. a 442. True 443. c 444. Yes 445. Yes 446. False 447. False 448. True 449. True 450. False
