MCQ
41. The slope of a stress-strain curve in the elastic deformation region is-
elastic modulus
plastic modulus
poison's ratio
none of the above
42. An ideal machine is one whose efficiency is- [BREB-15]
ব্যাখ্যা: The machine whose efficiency is 100% and in which friction is totally absent or Zero, is called as ideal machine. = 100%
between 60 and 70%
between 70 and 80%
between 80 and 90%
100%
43. The process of finding out the resultant force is called -----of force.
Composition
Resolution
44. The ratio of linear stress to linear strain is --[MES-18,BADC-18]
bulk modulus
modulus of rigidity
poisson's ratio
modulus of elasticity
none
45. Two forces are acting at an angle of 120°. The bigger force is 40N and the resultant is perpendicular to the smaller one. The smaller force is-
20N
40N
80N
none of this
46. If the resultant of a number of forces acting on a body is 0. Then the body will be equilibrium........
Yes
No
47. An irregular body may have more than one centre of gravity.....
Yes
No
48. The resultant of two forces P & Q is R. If Q is doubled, the new resultant is perpendicular to P. Then-
P=Q
Q=R
Q=2R
none of these
49. A force while acting on a body may-
Change its motion
Balance the force
Internal stress rise
All of this
50. The angles between two forces when the resultant is maximum & minimum respectively are-
0° & 180°
180° & 0°
90° & 180°
90° & 0°
51. Which is not a unit of stress? [MES-16]
Stress is a force that tends to deform the body on which it acts per unit area. It is measured in N/m² and this unit is specifically called pascal (Pa).
Unit of stress N/m², Pa, MPa, Psi
Unit of force =N (Newton).
Pa
N
psi
MPa
52. The friction experienced by a body, when at rest, is known as- (BREB-15]
ব্যাখ্যা: Static friction is the force of friction experienced by a body when it is at rest it is the value of the limiting friction just be fore slipping occurs.
static friction
coefficient of friction
dynamic friction
limiting friction
53. Hook's law holds good up to ----[BADC 18]
elastic limit
breaking point
plastic limit
yeild point
none
54. 1kg force is equal to-
7.8N
12N
8.91 N
9.81N
55. Two parallel sides of a trapezium are a and b, its height is h, its CG from base is at--- [MES-16]
π(a+b)/3h
h/3 (b+2a/b+a)
3/8(b+a /a+2b)
2h/3 b+2a/b+a
56. Whenever a material is loaded within elastic limit, stress is-strain. [BREB-15]
ব্যাখ্যা: Hook's law states that strain is directly proportional to strain produced by the stress when a material is loaded within the elastic limit.
equal to
directly proportional to
inversely proportional to
None of these
57. The center of gravity of a semi-circle lies at a distance of ----from its base measured along the vertical radius. 8r
3r/8
3r/4π
4r/3π
8r/3
58. A smooth cylinder lying on its convex surface remains in- equilibrium.
stable
neutral
unstable
none of these
59. The resultant of two equal force P making an angle θ, is given by-
2P sinθ/2
2P cosθ/2
2P tanθ/2
2P cot-θ/2
60. The terms 'leverage' & 'mechanical advantage' of a compound lever have got same meaning-----
Right
Wrong