Machine Design MCQ with Answers

191) In levers, leverage is the ratio of

Answer is:

effort arm to the load arm

192) The diameter of washer is generally taken bigger than the nut size.

Answer is:

Right

193) Which of the following statement is wrong?

The pitch of rivets is obtained by equating the tearing resistance of the plate to the shearing resistance of the rivets

The pitch of rivets should not be less than 2 d, where d is the diameter of rivet hole

The maximum value of the pitch of rivets for a longitudinal joint of a boiler, as per I.B.R., is given by P_max = C.t + 41.28 mm

According to I.B.R., the thickness of butt strap shall not be less than 5 mm

Answer is:

According to I.B.R., the thickness of butt strap shall not be less than 5 mm

194) If a shaft made from ductile material is subjected to combined bending and twisting moment, calculations based on which one of the following failure theories will give the most conservative value?

Answer is:

Maximum principal stress theory

195) Which of the following property is desirable in parts subjected to shock and impact loads?

Answer is:

Toughness

Explanation:

Toughness: When a huge external force is applied on a metal, the metal will experience fracture. Toughness is the ability of a metal to resist fracture. The ability of a material to resist fracture due to high impact loads, is called toughness.

Brittleness
Brittleness is a property of material which breaks with little or no deformation.

Stiffness: When an external force is applied on a metal, it develops an internal resistance. The internal resistance developed per unit area is called stress. Stiffness is the ability of a metal to resist deformation under stress.

Strength: When external forces are applied on a metal, breaking (brittle metal) or yielding (ductile metal) may occur. Strength is the property of a metal by which it resists external force without breaking or yielding.