RRB JE Previous questions

RRB 28th August Shift 2

1. For an ideal gas the value of Joule Thomson coefficient is

A. Zero B. 0.5

C. Unity D. Infinite

Ans. A.

2. Perpetual motion machine of second kind violates the

A. First law of thermodynamics

B. Kelvin-plank statement

C. Clausius statement

D. Third law of thermodynamics

Ans. B.

3. The ratio of thermal conductivity to electrical conductivity is equal to

A. Prandtl number B. Schmidt number

C. Lorentz number D. Lewis number

Ans. C.

4. The effectiveness of a fin will be maximum in a environment with

A. Free convection

B. Forced convection

C. Radiation

D. Convection and radiation

Ans. A.

5. With increasing temperature of intake air, IC engine efficiency

A. Decreases

B. Increases

C. Remains same

D. Depends on other factors

Ans. A.

6. Thermal efficiency of CI engine is higher than that of SI engine due to

A. Fuel used

B. Higher compression ratio

C. Constant pressure heat addition

D. Lower compression ratio

Ans. B.

7. The float in the carburettor of a petrol engine controls

A. Flow rate of air

B. Flow rate of fuel

C. Flow rate of air-fuel mixture

D. Level of the petrol in the float chamber

Ans. D.

8. Angle between the face and flank of the single point cutting tool is known as

A. Rake angle B. Clearance angle

C. Lip angle D. Point angle

Ans. C.

9. Which of the following is a cutting tool material

A. High speed steel B. Mild steel

C. Cost iron D. Galvanized steel

Ans. A

10. In milling machine, the cutting tool is held in position by

A. Chuck B. Spindle

C. Arbor D. Tool holder

Ans. C.

11. Collapsible tooth paste tubes are manufactured by

A. Direct extrusion

B. Piercing

C. Impact extrusion

D. Indirect extrusion

Ans. C.

12. Sprue in casting refers to

A. Gate B. Runner

C. Riser D. Vertical passage

Ans. D.

13. In arc welding, arc is created between the electrode and work by

A. Flow of current

B. Voltage

C. Material characteristics

D. Contact resistance

Ans. D.

14. Preheating of work piece is essential in welding

A. High speed steel

B. Stainless steel

C. Cast iron

D. Aluminium

Ans. C.

15. An ideal voltage source should have

A. large value of emf

B. small value of emf

C. zero source resistance

D. infinite source resistance

Ans. C.

16. Which bulbs operates on lowest power

A. Night bulb B. Neon bulb

C. GLS bulb D. Torch bulb

Ans. D.

17. Electrode in not consumed in the case of

A. TIG welding

B. MIG welding

C. Gas welding

D. Resistance welding

Ans. A.

18. DC generator are installed near the load centres to reduce.

A. iron losses

B. line losses

C. sparking

D. corona losses

Ans. B.

19. In a DC motor, constant torque is produced due to

A. rotor laminations B. end plates

C. pole shoes D. commutator

Ans. D.

20. Which of the following is not a part of transformer.

A. Conservator B. Buccholz Relay

C. Exciter D. Breather

Ans. C.

21. An induction motor is

A. self starting with zero torque

B. self starting with high torque

C. self starting with low torque

D. non self starting

Ans. C.

22. The term “cogging” is associated with

A. three phase transformer

B. compound generators

C. DC series motor

D. Induction motors

Ans. D.

23. The speed of universal motor is generally reduced by using

A. gear trains B. V-belts

C. brakes D. chains

Ans. A.

24. A thermal protection switch can protect against

A. short circuit B. temperature

C. over load D. Variable load

Ans. C.

25. In a bipolar transistor which current is largest

A. collector current

B. base current

C. emitter current

D. base or emitter current

Ans. C.

26. The word enhancement mode is associated with

A. tunnel diode B. MOSFET

C. photodiode D. varactor diode

Ans. B.

27. Which of the following has highest resistivity?

A. Mica B. Paraffin

C. Air D. Mineral oil

Ans. C.

28. Power diodes are generally

A. silicon diodes

B. germanium diodes

C. carbon diodes

D. carbon or germanium diodes

Ans. A.

29. The depletion layer width of junction

A. decreases with light doping

B. is independent of applied voltage

C. increases under reverse bias

D. increases with heavy doping

Ans. C.

30. For mercury arc rectifiers, the anode is usually made up of

A. aluminium B. graphite

C. tungsten D. copper

Ans. B.

31. For effective modulation, the degree of modulation should

A. small

B. never exceed 100%

C. be large

D. always more than 100%

Ans. B.

32. Which of them radiates emission?

A. LED

B. LCD

C. Both LCD and LED

D. Neither LCD nor LED

Ans. A.

33. Binary 101010 is equivalent to decimal number

A. 24 B. 42

C. 64 D. 44

Ans. B.

34. The number of valence electrons in donor impurity are

A. 1 B. 3

C. 5 D. 7

Ans. C.

35. A prismatic beam has uniform

A. Depth B. Width

C. Strength D. Cross-section

Ans. D.

36. A well graded soil has a coefficient of curvature between

A. 10 to 12 B. 7 to 9

C. 4 to 6 D. 1 to 3

Ans. D.

37. How is the deflection in RC beams controlled as per IS : 456?

A. By using large aspect ratio

B. By using small modular ratio

C. By controlling span/depth ratio

D. By moderating water-cement ratio

Ans. C.

38. A steel beam supporting loads from the floor slab as well as from wall is termed as

A. Stringer beam

B. Lintel beam

C. Spandrel beam

D. Header beam

Ans. C.

39. The dimensions of dynamic viscosity μ are

A. ML–1 T–2 B. ML–1 T–1

C. MLT–2 D. M°L°T°

Ans. B.

40. The representative fraction 1/2500 means that the scale 1 cm is equal to

A. 0.25 m B. 2.5 m

C. 25 m D. 2.5 km

Ans. C.