64. A refvigerator takes an electrical power of 150 Watts and rejects 450 Watts to surrounding
air. The coefficient of performance of refrigerator 18 :

ക 158 (B) 08
© 8 ™ 2

65. Which one of the following is a CFC refrigerant?
കര 8744 (18) 18290
(C) R502 (D) ೫718

66. Tooth interference in an external involute spur gear pair can be reduced by:
(ಗೆ) Decreasing center distance between gear pair
(ए) Increasing pressure angle
(0) Decreasing module
() Decreasing number of gear teeth |

67. The following data refers to two crossed helical gears used for speed reduction. Gear I: Pitch
circle diameter in the plane of rotation 80 mm and helix angle 30°. Gear II: Pitch ಯ
diameter in the plane of rotation 120 mm and helix angle 22.5° If the input speed is
1280 rpm, the output speed in rpm is : &

(ക) 900 rpm (B) 950 rpm
(C) 800 rpm (D) 850 rpm

68. A clutch has outer and inner diameters 100 mm and 40 mm respectively. Assuming a
uniform pressure of 2 MPa and coefficient of friction of liner material 0.4, the torque carrying
capacity of clutch 15 :

(ക 148 Nm (B) 490 Nm
(0 378 ೫ (D) 196 Nm

69. If the equilibrium speed of a governor is constant for all radii of rotation of the fly balls
within the working range, it is known as :

(ക) Isochronism (B) Hunting
(C) Insensitiveness (D) Stability

70. The gyroscopic couple of a suspended disc rotating at 1000 rpm is 15 N-m and the moment of
inertia is 0.4 kg-m?, then the precession veloeity of the disc in rad/sec is close to :

(ಗಿ) 0.38 (8) 35
(© 8.5 യ 0.0375
71 The fraction of unbalanced mass used for primary balancing of a reciprocating engine is :
(ക 0.2 () 0.9
(©) 06 (D) 0.05
A _ 11 028/2016

மா.)