A. nature of surfaces
B. area of contact
C. shape of the surfaces
D. ail of the above.
E. A. and B. above
Related Mcqs:
- Dynamic friction as compared to static friction is __________________?
A. same
B. more
C. less
D. may be less of more depending on nature of surfaces and velocity
E. has no correlation - Coulomb friction is the friction between_____________________?
A. bodies having relative motion
B. two dry surfaces
C. two lubricated surfaces
D. solids and liquids
E. electrically charged particles - A particle inside a hollow sphere of radius r, having coefficient of friction -rr can rest upto height of___________________?
A. r/2
B. r/A
C. r/%
D. 0.134 r
E. 3r/8 - The effort required to lift a load W on a screw jack with helix angle a and angle of friction <j) is equal to__________________?
A. Wtan(a + )
B. Wtan(a-)
C. Wcos(a + )
D. Wsin(a + )
E. W (sin a + cos ). - The buckling load for a given material depends on___________________?
A. slenderness ratio and area of cross-section
B. Poisson’s ratio and modulus of elasticity
C. slenderness ratio and modulus of elasticity
D. slenderness ratio, area of cross-section and modulus of elasticity
E. Poisson’s ratio and slenderness ratio - If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either___________________?
A. meet in a point
B. be all parallel
C. at least two of them must meet
D. all the above are correct
E. none of the above - A single force and a couple acting in the same plane upon a rigid body_________________?
A. balance each other
B. cannot balance each other
C. produce moment of a couple
D. are equivalent
E. none of the above - For steel, the ultimate strength in shear as compared to in tension is nearly _________________?
A. same
B. half
C. one-third
D. two-third
E. one-fourth - The safe twisting moment for a compound shaft is equal to the _________________?
A. maximum calculated value
B. minimum calculated value
C. mean value
D. extreme value
E. none of the above - The ratio of elongation in a prismatic bar due to its own weight (W) as compared to another similar bar carrying an additional weight (W) will be _________________?
A. 1:2
B. 1 : 3
C. 1 : 4
D. 1 : 2.5
E. 1 : 2.25
