83) The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is

84) Which of the following is the example of lever of first order

85) A pair of smith′s tongs is an example of the lever of

86) In the lever of third order, load W, effort P and fulcrum F are oriented as follows

87) The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of