A. P/2 cos 9/2

B. IP sin 9/2

C. 2P tan 9/2

**D. IP cos 9/2**

E. Psin 9/2

# Strength of Materials

## The weight of a body is due to____________________?

A. centripetal force of earth

B. gravitational pull exerted by the earth

C. forces experienced by body in atmos-phere

D. force of attraction experienced by par-ticles

**E. gravitational force of attraction towards the centre of the earth**

## Which of the following is not the unit of distance ?

A. angstrom

B. light year

C. micron

D. millimeter

**E. milestone**

## According to principle of moments_________________?

A. if a system of coplanar forces is in equilibrium, then their algebraic sum is zero

**B. if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero**

C. the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point

D. positive and negative couples can be balanced

E. none of the above

## According to Lami’s theorem________________?

A. three forces acting at a point will be in equilibrium

B. three forces acting at a point can be represented by a triangle, each side being proportional to force

C. if three forces acting upon a particle are represented in magnitude and

direction by the sides of a triangle, taken in order, they will be in equilibrium

**D. if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two**

E. none of the above

## Which of the following is not the unit of energy________________?

A. kg m

B. kcal

**C. wattr**

D. watt hours

E. kg m x (m/sec)2

## The effort required to lift a load W on a screw jack with helix angle a and angle of friction <j) is equal to_________________?

**A. Wtan(a + )**

B. Wtan(a-)

C. Wcos(a + )

D. Wsin(a + )

E. W (sin a + cos )

## The magnitude of two forces, which when acting at right angle produce resultant force of VlOkg and when acting at 60° produce resultant of Vl3 kg. These forces are____________________?

A. 2 and V6

B. 3 and 1 kg

**C. V5andV5**

D. 2 and 5

E. none of the above

## 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________________?

**A. density of metal can’t be determined**

B. metal is twice as dense as water

C. metal will float in water

D. metal is twice as dense as unknown fluid

E. none of the above

## Center of gravity of a thin hollow cone lies on the axis at a height of________________?

A. one-fourth of the total height above base

**B. one-third of the total height above base**

C. one-half of the total height above base

D. three-eighth of the total height above the base

E. none of the above