Two identical ball bearings P and Q are operating at loads 30KN and 45KN respectively. The ratio of the life of bearing P to the life of bearing Q is

1.  81/16

2.  27/8

3.  9/4

4.   3/2

4

27/8

Explanation :
No Explanation available for this question

Starting friction is low in

1.  Hydrostatic lubrication

2.   Hydrodynamic lubrication

3.  Mixed(or semi-fluid)lubrication

4.  Boundary lubrication

4

Hydrostatic lubrication

Explanation :
No Explanation available for this question

A band brake having band width of 80 mm, drum diameter of 250 mm, coefficient of friction 0.25 and angle of wrap of 270 degrees is required to exert a friction torque of 1000 N-m. The maximum tension in (in kN) developed in the band is

1.  1.88

2.  3.56

3.  6.12

4.  11.56

4

11.56

Explanation :
No Explanation available for this question

Axial operation claw clutches having self-locking tooth profile

1.  Can be disengaged at any speed

2.   Can be disengaged only when unloaded

3.  Can be engaged only when unloaded

4.  Can work only with load

4

Can be disengaged at any speed

Explanation :
No Explanation available for this question

A solid disc of radius r rolls without slipping on a horizontal floor with angular velocity ω and angular acceleration α. The magnitude of the acceleration of the point of contact on the disc is

1.  Zero

2.  rα

3.

4.  rω2

4

2

Explanation :
No Explanation available for this question

A link OB is rotating with a constant angular velocity of 2 rad/s in counter clockwise direction and a block is sliding radially outward on it with an uniform velocity of 0.75 m/s with respect to the rod, as shown in the figure below. If OA = 1m, the magnitude of the absolute acceleration of the block at location A in m/s2 is

1.  3

2.  4

3.   5

4.  6

4

5

Explanation :
No Explanation available for this question

A planar closed kinematic chain is formed with rigid links PQ = 2.0 m, QR = 3.0 m, RS = 2.5 m and SP = 2.7 m with all revolute joints. The link to be fixed to obtain a double rocker (Rocker – rocker) mechanism is

1.  PQ

2.  QR

3.  RS

4.  SP

4

RS

Explanation :
No Explanation available for this question

Instantaneous center of a body rolling with sliding on a stationary curved surface is

1.  At the point of contact

2.  On the common normal at the point of contact

3.  On the common tangent at the point of contact

4.  A the center of curvature of the stationary surface

4

On the common normal at the point of contact

Explanation :
No Explanation available for this question

The following are the data for two crossed helical gears used for speed reduction: Gear 1: Pitch circle diameter in the plane of rotation 80mm and helix angle 30° Gear II: Pitch circle diameter in the plane of rotation 120mm and helix angle 22.5° If the input speed is 1440 rpm. The output speed in rpm is

1.  1200

2.  900

3.  875

4.   720

4

900

Explanation :
No Explanation available for this question

1.  395

2.  790

3.  1580

4.  3160

4