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
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
A beam is loaded as cantilever. If the load at the end is increased, the failure will occur ___________________?
(A) in the middle
(B) at the tip below the load
(C) at the support
(D) anywhere
(D) 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
(D) 1 : 2.25
In riveted boiler joints, all stresses, shearing, bearing and tensile are based on the_________________?
(A) size of rivet
(B) size of the drilled or reamed hole
(C) average of size of rivet and hole
(D) smaller of the two
(D) any one of the above
Efficiency of a riveted joint is the ratio of its strength (max. load it can resist without failure) to the strength of the unpunched plate in_________________?
(A) tension
(B) compression
(C) bearing
(D) any one of the above
(D) none of the above
A riveted joint in which every rivet of a row is opposite to other rivet of the outer row, is known as______________________?
(A) chain riveted joint
(B) diamond riveted joint
(C) criss-cross riveted joint
(D) zig-zag riveted joint
(D) none of the above