16.When the intermolecular distance decreases due to compressive force, there is:

17.A string 1 mm in diameter breaks if the tension in it exceeds 80 N. The maximum tension that may be given to a similar string of diameter 2 mm is

18.A wire elongates by l mm when a load w is hanged from it. If the wire goes over a pulley and two weights w each are hung at the two ends, the elongation of the wire will be (in mm):

19.A wire can sustain a weight of 10 kg before breaking. If the wire is cut into two equal parts, then each part can sustain a weight of

20.The length of an elastic string is a metre when the tension is 4 N, and b metre when the tension is 5 N. The length in metres when the tension is 9 N, is: