Mechanical Engineering MCQs

Thermosetting plastics are those materials which

by
are formed into shape under heat and pressure and results in a permanently hard product
do not become hard with the application of heat and pressure and no chemical change occurs
are flexible and can withstand considerable wear under suitable conditions
are used as a friction
✅ The correct answer is option A.

A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)

by
P = W tan α
P = W tan (α + φ)
P = W (sin α + μ cos α)
P = W (cos α + μ sin α
✅ The correct answer is option C.