12) When the connection between the two elements is such that only required kind of relative motion occurs, it is known as self-closed pair.

13) The Whitworth quick return motion mechanism is formed in a slider crank chain when the

14) The primary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is

15) The acceleration of the particle moving with simple harmonic motion is inversely proportional to the displacement of the particle from the mean position.

16) The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ?₁ rad/s in the clockwise direction and the link OB turns with angular velocity ?₂ rad/s in the c