Theory of Machine
For a kinematic chain to be considered as mechanism

There is no such criterion
None of the links should be fixed
One link should be fixed
Two links should be fixed

ANSWER DOWNLOAD EXAMIANS APP

Theory of Machine
The secondary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the length of connecting rod to radius of crank)

m.ω².r (sin 2θ/n)
m.ω².r sinθ
m.ω².r (cos 2θ/n)
m.ω².r cosθ

ANSWER DOWNLOAD EXAMIANS APP