স্ট্রাকচারাল মেকানিক্স MCQ
41. 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
42. 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
43. The resultant of two force P & Q acting at an angle θ is-
√P^2+Q^2+2PQsinθ
√P^2+Q^2+2PQcosθ
√P^2+Q^2-2PQcosθ
44. A force while acting on a body may-
Change its motion
Balance the force
Internal stress rise
All of this
45. 1kg force is equal to-
7.8N
12N
8.91 N
9.81N
46. The process of finding out the resultant force is called -----of force.
Composition
Resolution
47. 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%
48. 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
49. The terms 'leverage' & 'mechanical advantage' of a compound lever have got same meaning-----
Right
Wrong
50. The angles between two forces when the resultant is maximum & minimum respectively are-
0° & 180°
180° & 0°
90° & 180°
90° & 0°
51. The center of gravity of a right circular solid cone is at a distance of---- from its base, measured along the vertical axis.
h/2
h/3
h/4
h/6
52. 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
53. 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
54. A smooth cylinder lying on its convex surface remains in- equilibrium.
stable
neutral
unstable
none of these
55. If the resultant of a number of forces acting on a body is 0. Then the body will be equilibrium........
Yes
No
56. If the resultant of two force P & Q acting at an angle θ, makes an angle α with force P, then-
tanα = P sinθ / P+Q cosθ
tanα = P cosθ / P+Q cosθ
tanα = Q sinθ / P+Q cosθ
57. 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
58. An irregular body may have more than one centre of gravity.....
Yes
No
59. 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
60. The slope of a stress-strain curve in the elastic deformation region is-
elastic modulus
plastic modulus
poison's ratio
none of the above