The co-efficient of friction depends upon _________________?
(A) nature of surfaces
(B) area of contact
(C) shape of the surfaces
(D) ail of the above.
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
(D) none of the above
The algebraic sum of moments of the forces forming couple about any point in their plane is__________________?
(A) equal to the moment of the couple
(B) constant
(C) both of above are correct
(D) both of above are wrong
(D) none of the above
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
(D) has no correlation
If rain is falling in the opposite direction of the movement of a pedestrain, he has to hold his umbrella ________________________?
(A) more inclined when moving
(B) less inclined when moving
(C) more inclined when standing
(D) less inclined when standing
(D) none of the above
In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be____________________?
(A) increase key length
(B) increase key depth
(C) increase key width
(D) double all the dimensions
(D) none of the above
The value of shear stress which is induced in the shaft due to the applied couple varies____________________?
(A) from maximum at the center to zero at the circumference
(B) from zero at the center to maximum at the circumference
(C) from maximum at the center to mini-mum at the cricumference
(D) from minimum at the centro to maxi-mum at the circumference
(D) none of the above
A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to_________________?
(A) 25
(B) 50
(C) 100
(D) 250
(D) 500
The C.G. of a solid hemisphere lies on the central radius 3r_________________?
(A) at distance — from the plane base 3r
(B) at distance — from the plane base 3r
(C) at distance — from the plane base 3r
(D) at distance — from the plane base or
(D) at distance — from the plane base
The C.G. of a right circular solid cone of height h lies at the following distance from the base________________?
(A) h/2
(B) J/3
(C) h/6
(D) h/4
(D) 3/i/5