61. Pressure angles more than 25° are not used in involute profiles because

1. The gears are difficult to manufacture

2. Minimum number of teeth for under cutting increases enormously

3. Bearing radial load from normal reaction between gears will be very high

(a) 1 only

(b) 2 only

(c) 3 only

(d) 1, 2 and 3

Answer: (c)

62. 

Answer: (c)

63. At a point in a bi-axially loaded member, the principal stresses are found to be 60 MPa and 80 MPa. If the critical stress of the material is 240 MPa, what could be the factor of safety according to the maximum shear stress theory?

(a) 2

(b) 3

(c) 4

(d) 5

Answer: (b)

64. The difference between member of a truss and of a beam is:

(a) The members of a truss take their loads along their length whereas a beam takes loads at right angles to its length

(b) The member of the truss takes load lateral to its length whereas the beam along the length

(c) The member of the truss can be made of C.I where as the beam is of structural steel only

(d) The member of the truss can have a circular cross-section whereas the beam can have any cross-section

Answer: (a)

65. Statement (I): When a liquid is poured in different shaped vessels with base area same and equal height, the apparent contradiction of equal force at base, but different weights of liquids is hydrostatic paradox.

Statement (II): Bernoulli’s equation is valid for inviscid liquids.

(a) Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

(b)Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

(c) Statement (I) is true but Statement (II) is false

(d)Statement (I) is false but Statement (II) is true

Answer: (b)

66. A bar of mild steel 200 𝑚𝑚 long and 50 𝑚𝑚 ×50 𝑚𝑚 in cross section is subjected to an axial load of 200 kN . If E is 200 GPa, the elongation of the bar will be

(a) 0.16 𝑚𝑚

(b) 0.08 𝑚𝑚

(c) 0.04 𝑚𝑚

(d) 0.02 𝑚𝑚

Answer: (b)

67. A simply supported beam of span 𝑙 carries over its full span a load varying linearly from zero at each end to 𝑊 𝑁/𝑚 at midspan. The maximum bending moment is


Answer: (a)

68. A cantilever beam of length 𝑙 carries a load (𝑊=𝜔l ) uniformly distributed over its entire length. If the same total load 𝑊 is placed at the free end of the same cantilever, then the ratio of maximum deflection in the beam in the first case to that in the second case will be:

(a) 3/12

(b) 3/8

(c) 3/4

(d) 3/2

Answer: (b)

69. In theory of simple bending an assumption is made that plane sections before bending remain plane even after bending. This assumption implies that

(a) Strain is uniform across the section

(b) Stress is uniform across the section

(c) Stress in any layer is proportional to its distance from the neutral axis

(d) Strain in any layer is directly proportional to its distance from the neutral axis

Answer: (d)

70. Consider the following statements about 𝐼𝐼 sections:

1. The flange carries maximum bending load

2. The web carries maximum bending load

3. It is ideal in one unique plane of bending

4. It is ideal for both planes of bending normal to each other

Which of the above statements are correct?

(a) 2 and 3 only

(b) 2 and 4 only

(c) 1 and 3 only

(d) 1 and 4 only

Answer: (c)