291) The equivalent length of a simple pendulum depends upon the distance between the point of suspension and the centre of gravity.

293) When the nature of contact between the elements of a pair is such that one element can turn about the other by screw threads, the pair is known as a

294) In a locomotive, the resultant unbalanced force due to the two cylinders along the line of stroke, is known as

295) When no external force acts on a body, after giving it an initial displacement, the body is said to have free vibrations.

296) Which of the following is an example of sliding pair?