Question 1: As per junction growth in metallic friction :

A. Increase in tangential force increases the real area of contact.

B. Increase in interface shear strength decreases the growth of the junction.

C. Liquid lubricant enters in crevices and increases the growth rate of junction.

D. At low temperature due to freezing action rate of junction growth increases.

(A)
(B)
(C)
(D)

Question 2 : Which of the following related to Stick-Slip phenomenon is INCORRECT?

A. It causes catastrophic wear failure.

B. It may occur where coefficient of kinetic friction is lesser than coefficient of static friction.

C. It depends on relative velocity.

D. It can be avoided by proper lubrication.

(A)
(B)
(C)
(D)

Question 3: Which of the following condition for selection of coating under un-lubricated sliding pair is INCORRET?

A. Lower adhesion to substrate.

B. More Hardness.

C. Lower surface roughness.

D. Less change in dimensions during surface treatment.

(A)
(B)
(C)
(D)

Question 4: Molecular attraction between metals result in

A. Cold welding of surfaces

B. Abrasion

C. Erosion

D. Corrosion

(A)
(B)
(C)
(D)

Question 5: Arrange following in order of occurrence (i) Junction failure (ii) merging of two particles (iii) secondary contact (iv) transfer of particle.

A. (i), (ii), (iii), (iv)

B. (ii),(i), (iii), (iv)

C. (i), (iv), (iii), (ii)

D. (iv), (ii), (iii), (i)

(A)
(B)
(C)
(C)

Question 6: When two surfaces are pressed together by a load, which of the following properties of soft material will affect the coefficient of friction between them ?

A. Shear strength

B. Hardness

C. Interface shear strength

D. All of above

(A)
(B)
(C)
(D)

Question 7: Which is not true about coefficient of friction?

A. More fluid shearing lesser the friction

B. Lesser roughness lesser friction

C. Lesser chemical affinity lesser friction

D. Lesser interface shear strength, lesser friction

(A)
(B)
(C)
(D)

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