198. Lubrication is done to control
A. Friction
B. Wear
C. Temperature
D. All of the above
✅ The correct answer is option D.
201. The phenomenon of weld decay is found in case of
A. Gun metal
B. Brass
C. Stainless steel
D. Cast iron
✅ The correct answer is option D.
204. Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails
A. Below the yield point
B. Above the yield point
C. Below the elastic limit
D. At the elastic limit
✅ The correct answer is option A.
207. Brittleness induced due to the presence of sulphur in steel can be reduced by adding
A. Manganese
B. Magnesium
C. Vanadium
D. Copper
✅ The correct answer is option A.
162. Powder metallurgy technique is used in the production of __________ tools.
A. Tungsten carbide
B. High carbon steel
C. High speed steel
D. Drilling
✅ The correct answer is option A.
165. __________ the exhaust gas is an indication of the incomplete combustion of fuel.
A. Low temperature of
B. High temperature of
C. High % of CO in
D. High % of CO₂ in
✅ The correct answer is option C.
168. The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe)
A. A
B. D
C. 1/A
D. 1/A²
✅ The correct answer is option C.
171. The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the ‘Curie point’, which is __________ °C.
A. 768
B. 908
C. 1400
D. 1539
✅ The correct answer is option A.
174. Which of the following is not a natural abrasive?
A. Silicon carbide
B. Quartz
C. Corundum
D. Emery
✅ The correct answer is option A.
177. The normal stress is the same in all directions at a point in a fluid, only when the fluid
A. Is at rest & has zero viscosity
B. Is frictionless
C. Fluid layer has no motion relative to an adjacent layer of fluid
D. Is incompressible & frictionless
✅ The correct answer is option D.