52. A triangular section having base b, height h, is placed with its base horizontal. If the shear stress at a depth y from top is q, the maximum shear stress is
3S/bh
4S/bh
4b/Sh
3b/bS
Correct answer: (A) 3S/bh
53. 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
Correct answer: (C) 4.0 cm
54. A uniform girder simply supported at its ends is subjected to a uniformly distributed load over its entire length and is propped at the centre so as to neutralise the deflection. The net B.M. at the centre will be
WL
WL/8
WL/24
WL/32
Correct answer: (D) WL/32
55. 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
Correct answer: (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
56. According to law of triangle of forces
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
Correct answer: (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
57. According to principle of moments
If a system of coplanar forces is in equilibrium, then their algebraic sum is zero
If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
The algebraic sum of the moments of any two forces about any point is equal to moment of their resultant about the same point
Positive and negative couples can be balanced
Correct answer: (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
58. According to principle of transmissibility of forces, the effect of a force upon a body is
Maximum when it acts at the center of gravity of a body
Different at different points in its line of action
The same at every point in its line of action
Minimum when it acts at the C.G. of the body
Correct answer: (C) The same at every point in its line of action
59. According to Unwin's formula, the diameter 'd' of a rivet of plate of thickness 't' is:
d = 6.05 √t
d = 1.5 t + 4
d = √5 t
d = √t + 1.5
Correct answer: (A) d = 6.05 √t
60. Along the neutral axis of a simply supported beam