1. The weight of an object will be maximum when it is placed at
Correct : D. Centre of earth
2. A grinding wheel rotates at 3000 rpm. When power supply is cut off the wheel stops in 5 sec. The number of revolutions made by the wheel before coming to rest would be
Correct : C. 250
3. A solid spherical ball rolls on a table. The momen' of inertia of the ball is given by 3/5 x mass x radius2. The ratio of translational and rotational kinetic energies for ball will be
Correct : C. 5?3
4. A particle inside a hollow sphere of internal radius r with coefficient of friction 1/?3 can rest upto height of
Correct : D. 0.134 r
5. A particle starts from rest and moves in a straight line whose equation of motion is given by S = 2t3 - t2 - 1. The acceleration of the particle after one sec will be
Correct : D. 10 m/sec2
6. An electric motor drives a windless which hauls up a crate A of weight W = 500 kg up an inclined plane through a height of 10 m in 2 minutes. The torque acting on the windless is 25 kgm and the drum of the windless makes 30 rpm. The efficiency of the inclined plane would be
Correct : D. 53.05%
7. A screw jack has 4 threads per inch. The mean radius of the thread is 2.338 inches. The mean diameter of the bearing surface under the cap is 3.25 inches. What is the turning moment required to raise the bload of 150 kg
Correct : B. 50.6 kg-inch
8. The length of Seconds Pendulum is
Correct : C. 994 mm
9. The law of conservation of mechanical energy is valid
Correct : C. Only if the total work done by the particle in moving around in a closed trajectory is zero
10. In above case the maximum height attained by the ball would be