Questions and answers for exam Preparation

MCQs

Total Questions : 735 | Page 9 of 74 pages

Question 81. According to Lami's theorem

Three forces acting at a point will be in equilibrium
Three forces acting at a point can be represented by a triangle, each side being proportional to force
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
If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

Discuss Question

Answer: Option 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

Question 82. Which one of the following statements is not correct

the tangent of the angle of friction is equal to coefficient of friction
the angle of repose is equal to angle of friction
the tangent of the angle of repose is equal to coefficient of friction
the sine of the angle of repose is equal to coefficient to friction

Discuss Question

Answer: Option D. -> the sine of the angle of repose is equal to coefficient to friction

Question 83. If a suspended body is struck at the centre of percussion, then the pressure on die axis passing through the point of suspension will be

Maximum
Minimum
Zero
Infinity

Discuss Question

Answer: Option C. -> Zero

Question 84. 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

Discuss Question

Answer: Option B. -> cannot balance each other

Question 85. Center of gravity of a solid cone lies on the axis at the height

one-fourth of the total height above base
one-third of the total height above base
one-half of the total height above base
three-eighth of the total height above the base

Discuss Question

Answer: Option A. -> one-fourth of the total height above base

Question 86. A semi-circular disc rests on a horizontal surface with its top flat surface horizontal and circular portion 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

Discuss Question

Answer: Option C. -> slant down towards direction of pull

Question 87.

For a given material, if E, C, K and m are Young's modulus, shearing modulus, bulk modulus and poisson ratio, the following relation does not hold good

` E = (9 K C)/(3K + C)`
`E = 2K ( 1 - 2/m)`
`E = 2C( 1 +1/m)`
`1/m = (3K - 2C)/(6K + 2C)`
`E = 3C ( 1 - 1/m)`

Discuss Question

Answer: Option C. -> `E = 2C( 1 +1/m)`

Question 88.

According to Unwin's formula, the diameter d of a rivet of plate of thickness t is :

` d = 6.05sqrt( t)`
d = 1.5 t + 4
d =`sqrt(5)` t
d = `sqrt(t)` + 1.5

Discuss Question

Answer: Option A. -> ` d = 6.05sqrt( t)`

Question 89.

If a member carries a tensile force P on its area of cross-section A, the normal stress introduced on an inclined plane making an angle `theta` with its transverse plane, is