250+ TOP MCQs on Hydrodynamics Step Bearing and Answers

Machine Design Multiple Choice Questions on “Hydrodynamics Bearings”.

Answer the questions 1-7 with respect to this figure

1. The bearing characteristic number shown in the graph is directly proportional to the unit bearing pressure.
a) True
b) False
Answer: b
Clarification: BCN=µN/P.

2. In the graph shown, which regions points the partial metal to metal contact.
a) BC
b) CD
c) Both BC and CD
d) Can’t be determined
Answer: a
Explanatiion: BC is the condition of thin film and hence surfaces are not completely separated.

3. Hydrodynamic lubrication takes place in region?
a) BC
b) CD
c) Both BC and CD
d) None of the mentioned
Answer: b
Clarification: In CD thick film of lubrication has developed.

4. Coefficient of friction is minimum at
a) It is same at each point
b) B
c) C
d) D
Answer: c
Clarification: It is minimum at the transition zone.

5. Bearing modulus is the bearing characteristic number at
a) B
b) C
c) D
d) None of the listed
Answer: b
Clarification: BCN modulus is the the BCN number corresponding to the minimum coefficient of friction.

6. If viscosity of the lubricant is very low than BCN will lie in the region
a) BC
b) Point C
c) CD
d) Can’t be determined
Answer: a
Clarification: Due to low viscosity, lubricant will not separate the two surfaces resulting in partial contact.

7. The fundamental equation for viscous flow is given by ∆pbhᵌ/6µl where symbols have their usual meanings.
a) 6 is to be replaced by 3
b) 6 is to be replaced by 12
c) 6 is to be replaced by 9
d) 6 is to be replaced by 15
Answer: b
Clarification: It is givenby ∆pbhᵌ/12µl.

8. A single transverse weld is preferred over double transverse fillet weld.
a) True
b) False
Answer: b
Clarification: A single transverse weld is not preferred because the edge of the plate which is not welded can warp out of shape.

9. Transverse fillet weld can be designed using the same equations as of parallel fillet weld.
a) True
b) False
Answer: b
Clarification: Vice versa is true as strength of transverse fillet weld is greater than that of parallel fillet weld.