KRL Sample Questions for Mechanical Engineering

KRL Sample Questions for Mechanical Engineering

Instructions:

• Write your full name and all other information asked at the top of this page and at the Answer sheet
provided.
• Encircle the letters A, B, C or D in the Answer Sheet corresponding to the correct answer from the
given options
• Each correct answer carries THREE marks while ONE mark will be deducted for each incorrect
answer.
• Use of any external paper for rough work is not allowed. Carry out your rough work somewhere in
the question paper. DO NOT use any side of the answer sheet for rough work.
• More than one answers for a single question will be considered as INCORRECT
• Fill the answer sheet carefully. Avoid overwriting and/or cutting in the answer sheet.
• Exchange of anything is not allowed during the examination
• STOP WRITING IMMEDIATELY when you are asked to do so
• KEEP YOUR MOBILE PHONES OFF AND POCKETED. USE OF MOBILE PHONE AS
CALCULATOR IS ALSO NOT ALLOWED.

• Be sure that you have got all the pages of your paper with 80 questions in all.

Sample Paper (MECHANICAL)

1. In a wind tunnel, the flow speeds (of air) on the upper and lower surfaces of the wing of a model airplane are v1and v2 respectively (v1> v2). If the wing area is A and the density of air is ρ, the lift on the wing is

(A) ρ (v12–v22)A

(B) 1⁄2 ρ (v1 –v2)A

(C) 1⁄2 ρ (v12–v22)A

(D) 1⁄2 (v12–v22)A/ρ

2. Oil has a kinematic viscosity of 1.25×10-04 m2/s and a specific gravity of 0.8. What is dynamic (absolute) the viscosity of the oil?

(A) 0.08kg/m-

(B) 0.10kg/m-

(C) 0.125kg/m-

(D) 1 kg/m-s

3. Inflow through a straight, smooth pipe, the diameter Reynolds number for the transition to turbulence is generally

taken to be

(A) 1500 (B) 2300 (C) 250,000 (D) 4000

4. Consider a liquid with density ρ, viscosity μ and velocity V flowing over a very small dam spillway of length L, such that surface tension coefficient σ is very important. The quantity 2 ρV L σ, in this case, is important and is called

(A) Weber number (B) Froude number

(C) Prandl number (D) Bond number

5. Minor losses through pipes, fitting, bend, etc. are commonly modeled as proportional to:

(A) Velocity Head

(B) Static Head

(C) Total Head

(D) Pressure Drop

6. What is the hydraulic diameter of the rectangular air conditioning duct whose cross-section is 1 m by 25 cm?

(A) 40 cm (B) 50 cm (C) 75 cm (D) 100 cm

7. Stress intensity factor ‘KI’, has the following relationship with the crack length ‘a’ in a material

(A) KI α a 

(B) KI α a 

(C) KI α 1a 

(D) KI α a2

8. The figure shows a pin-jointed plane truss loaded at the point M by hanging a mass of 100 kg. The member LN of the truss is subjected to a load of?

(A) 0 Newton

(B) 490 Newton in compression

(C) 981 Newton in compression

(D) 981 Newton in tension

9. The automobile exhaust will have a maximum of hydrocarbons when the vehicle is

(A) Idling (B) Cruising (C) Decelerating (D) Accelerating

10. The efficiency of vapor power Rankine cycle can be increased by

i. Increasing the temperature of the working fluid at which heat is supplied

ii. Increasing the pressure of the working fluid at which heat is supplied

iii. Decreasing the temperature of the working fluid at which heat is rejected

Which of the above statements is/are correct?

(A) i alone (B) ii and iii (C) i, ii and iii (D) i and ii