66. Arrange the given materials in increasing order of their Young's modulus of elasticity :
(i) Stainless Steel;
(1) Tungsten Carbide;
(1) Aluminium;
(iv) Cast Iron
(ல @ (iii) (11) Gv)
(8) 69) (ii) @) (iit)
(0 01) Gv) (1 0)
(D) 01) 0) (५) 0)

67. A steel bar 1m long and 20 mm > 10 mm cross-section is subjected to a tensile load of
10 KN along its longitudinal axis. If the modulus of elasticity is 2 x 105 N/mm? and
Poisson’s ratio is 0.3, the lateral strain is:

(A) 0.05 x 103 (B) 0.075 x 103
(©) 0.25» 104 (D) 0.025 x [0-4

68. Which of the following statements is not true about static friction 7
(A) | The force of friction depends upon the roughness of the surfaces.

(B) The direction of limiting frictional force is opposite to the direction of
motion.

(C) The magnitude of the limiting friction bears a constant ratio to the normal
reaction between the two surfaces.

(D) The force of friction is dependent on the area of contact between the two
surfaces.

69. The section modulus for a beam of circular section with diameter ‘d’ is:

nd? प्तः
A प py zd
ல்‌ 32 ಈ) 64
764 70
(^) — D) —
© 32 ©) 64

70. ൧ weld made to hold parts of a weldment in proper alignment until the final welds are
made is called

(^) Filled weld (B) Kerf
(C) Nugget (D) Tack weld

71. Incase of a circular shaft, the torque divided by the angle of twist per unit length is called
(A) _ torsional stiffness ‏رق‎ torsional rigidity
(C) polar modulus (D) torsional strain

005/2021 == ` 10 ↽↽ 89 9 7