Coulomb friction is the friction between_________________?
(A) bodies having relative motion
(B) two dry surfaces
(C) two lubricated surfaces
(D) solids and liquids
(D) electrically charged particles
Tangent of angle of friction is equal to_________________?
(A) kinetic friction
(B) limiting friction
(C) angle of repose
(D) coefficient of friction
(D) friction force
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 + )
(D) W (sin a + cos )
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
(D) 3r/8
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
(D) none of the above
The maximum frictional force which comes into play when a body just begins to slide over another surface is called_____________________?
(A) limiting friction
(B) sliding friction
(C) rolling friction
(D) kinematic friction
(D) dynamic friction
If n = number of members andy = number of joints, then for a perfect frame, n =_______________?
(A) j-2
(B) 2j-l
(C) 2/-3
(D) 3/-2
(D) 2/ -4
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
Which of the following is not the unit of energy________________?
(A) kg m
(B) kcal
(C) wattr
(D) watt hours
(D) kg m x (m/sec)2
In the equation of virtual work, following force is neglected_______________?
(A) reaction of any smooth surface with which the body is in contact
(B) reaction of a rough surface of a body which rolls on it without slipping
(C) reaction at a point or an axis, fixed in space, around which a body is con-strained to turn
(D) all of the above
(D) none of the above