11. A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Correct answer: (B)
parabola
12. A number of forces acting at a point will be in equilibrium if
Correct answer: (C)
sum of resolved parts in any two per-pendicular directions are both zero
13. A pair of smith's tongs is an example of the lever of
Correct answer: (C)
second order
14. A particle inside a hollow sphere of radius r, having coefficient of friction -rr can rest upto height of
Correct answer: (D)
0.134 r
15. A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t2 (t - 4), the acceleration of the particle will be given by the equation
Correct answer: (C)
6f-8
16. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is
Correct answer: (C)
45°
17. A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
Correct answer: (A)
density of metal can't be determined
18. A semi-circular disc rests on a horizontal surface with its top flat surface horizontal and circularportion touching down. The coefficient of friction between semi-cricular disc and horizontal surface is \i.This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will
Correct answer: (C)
slant down towards direction of pull
19. A single force and a couple acting in the same plane upon a rigid body
Correct answer: (B)
cannot balance each other
20. A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
Correct answer: (C)
4.0 cm