**11. **A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve

- catenary
- parabola
- hyperbola
- elliptical
- circular arc.

Correct answer: (B)

parabola

**12. **A number of forces acting at a point will be in equilibrium if

- their total sum is zero
- two resolved parts in two directions at right angles are equal
- sum of resolved parts in any two per-pendicular directions are both zero
- all of them are inclined equally
- none of the above.

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

- zeioth order
- first order
- second order
- third order
- fourth order.

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

- r/2
- r/A
- r/%
- 0.134 r
- 3r/8.

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

- 3t2-lt
- 3t2+2t
- 6f-8
- 6f-4
- 6t2-8t.

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

- 0°
- 30°
- 45°
- 60°
- 90°.

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

- density of metal can't be determined
- metal is twice as dense as water
- metal will float in water
- metal is twice as dense as unknown fluid
- none of the above.

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

- remain horizontal
- slant up towards direction of pull
- slant down towards direction of pull
- unpredictable
- none of the above.

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

- balance each other
- cannot balance each other
- produce moment of a couple
- are equivalent
- none of the above.

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

- 2.5 cm
- 3.0 cm
- 4.0 cm
- 5.0 cm
- 2.0 cm.

Correct answer: (C)

4.0 cm