RRB JOBS QUESTION BANK : JUNIOR ENGINEER (AC) SHORT ANSWER TYPE QUESTIONS
QUESTION BANK FOR SELECTION TO THE POST OF JUNIOR ENGINEER (AC)
SHORT ANSWER TYPE QUESTIONS:
1) What are the main components of Lead Acid Cell?
Ans. Main Components of Lead Acid Cells are:
a) Positive Plates which are tubular in shape made of PBO2
b) Negative Plates usually consists of a lead grid into which active material of Sponge lead is pressed.
c) Separators, which are made by Synthetic used between +ve and –ve plates.
d) Container is made of hard rubber or PPCP with high insulating strength to resist acids which are used as Electrolyte.
e) Cell covers which covers container having vent plugs and level indicator.
2) What is meant by SMF batteries?
Ans. To overcome problems of frequent Topping up and Leakage of Electrolyte. Sealed maintenance free batteries are developed Electrolyte in these batteries is in immobilized form and these can be used in any position that is horizontal or vertical.
3) What is significance of Green and Red mark of the float guide of Lead Acid ells?
Ans. The float stem will have markings to indicate the lowest in red and highest in green of permissible electrolyte levels. It should be ensured that the electrolyte level is maintained in service by adding pure distilled / dematerialized water.
4) What are the equipments available in PELE box and when they are utilized?
Ans. The equipments available in PELE box are:
01 TRIPOD STAND 05 BULBS
02 HOLDER 06 HAND LAMP
03 FLEXIBLE WIRE 25 METERS 07 LOG BOOK
04 CROCODILE CLIPS 08 LAMP FITTINGS
These are used in emergency conditions train service. This box is kept in the Guard Compartment.
5) What are the safety checks in under gear in AC Coaches?
Ans: Alternator safety chains, Suspension pin with anti- rotation plate, suspension pin with nylon bushes, Alternator pulleys, Axel pulley with bolts condition of battery box channels, nuts & bolts, WRA, Under Slung Inverter suspension arrangements and split pins of all under gear electrical uspension equipments.
6) How do check Pulleys of Axle & Alternator?
Ans: Axle pulleys nuts and bolts with split pins, condition of grooves, and gap between two halves of the axle pulleys. Alternator pulley castle nut with split pin.
7) What are the reasons for V-Belt dropping?
Ans: The reasons for V-belt dropping are may be due to locking of barrel bush, locking of alternator safety chains, misalignments of axle pulleys, Alternator bearing jam and due to cattle run over.
8) What are the schedule attentions on Lead Acid Batteries in FNE schedule?
Ans: Cleaning of ICC, toping up of distilled water, applying of petroleum jelly on terminals ports. Checking of SPG. Providing charging. Checking of ON load and OFF load voltage of individual cells and group.
9) What is meant by Specific Gravity in Cells & its significance?
Ans: SPG is the ratio of the density of electrolyte to the density of water fully charged lead acid cell will have a SPG of 1.250 and fully discharge cell 1.150.
10) What are the various defects noticed in Cells?
Ans: Open circuit, short circuits, container leakage, reverse polarity, low SPG and voltage.
11) What is the gap between the Mounting Bracket to adjustment nut in Tension device & how to adjust?
Ans: The gap between the Mounting Bracket to adjustment nut in Tension device is 75 mm & it can be adjusted by opening check nut and adjusting barrel bush.
12) Why earthing is necessary for any electrical equipments, domestic installation & service building etc?
Ans: To drain away any leakage of currents due to poor insulation and to save human life from dangerous shock and also to avoid burnt of electrical equipment.
13) What is the procedure for using Fire extinguisher?
Ans: a) Pull the pin at the top of the extinguisher.
b) Aim the nozzle towards the base of the fire.
c) Stand approximately 8 feet away from the fire and squeeze the handle to discharge the extinguisher.
d) Sweep the nozzle back and forth at the base of the fire.
14) Classification of low tension and high-tension lines with respect to voltages?
Ans: a) Low Voltage Lines = Less than 250V
b) Medium Voltage Lines = 250 V to 650V
c) High Voltage Lines = 650V to 33 KV
d) Extra High Voltage Lines = Above 33 KV
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Courtesy: Indian Railway