Dynamically Equivalent Link: this is link that has point masses at two points such that (a) overall mass is same, (b) centre of gravity is at the similar position, and (c) mass moment of inertia around an axis through CG remains similar.

Turning Moment: This is the moment of the force at crank pin w. r. t. the crank centre.

Turning Moment Diagram: this is the diagram plotted along turning moment on the Y-axis & angle of rotation of crank for one cycle on the X-axis.

Fluctuation of the Energy: this is the difference among the maximum energy at a point on the mean torque line & minimum energy at another point on the mean torque line.

Coefficient of the: this is the ratio of fluctuation of energy to the energy Fluctuation Energy of the cycle.

Fluctuation of Speed: This is the difference in minimum angular speed and maximum angular speed.

Coefficient of Fluctuation: This is the ratio of fluctuation of speed to the average of Speed angular speed.