Mechanical Engineering MCQs

In a differential band brake as shown in the below figure, the drum rotates anticlockwise and the greater tension T1 acts at A and smaller tension T2 at B. Length OA is greater than length OB. In order to apply the brake, the force P at C should

by
be zero
act in upward direction
act in downward direction
none of the above
✅ The correct answer is option C.

An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m2). The critical thickness of insulation will be

by
25 mm
40 mm
160 mm
800 mm
✅ The correct answer is option A.

In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien’s acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral C Q NO, if N coincides with O, then

by
acceleration and velocity of the piston P is zero
acceleration and velocity of the piston P is maximum
acceleration of the piston P is zero and its velocity is maximum
acceleration of the pi
✅ The correct answer is option C.