75.The attraction of unlike molecules at the common surface is known as
   (a) adhesion
   (b) cohesion
   (c) surface tension
   (d) capillarity
Ans: (a)
76.Mercury does not stick to glass because
   (a) cohesive forces between the mercury molecules are greater than adhesive
       forces between mercury and glass molecules
   (b) the adhesive forces between mercury and glass molecules are greater than
       the cohesive forces
   (c) both the cohesive and adhesive forces are equal
   (d) None of the above
Ans: (a)
77.In a river, the currents are fastest where the river la
   (a) wide and shallow
   (b) narrow and shallow
   (c) wide and deep
   (d) narrow and deep
Ans: (b)
78.Pieces of camphor placed on water move about rapidly. This is because of
   (a) diffusion
   (b) viscosity
   (c) surface tension
   (d) capillarity
Ans: (c)
79.In compact porous soil, the rising of the water is due to
   (a) capillarity
   (b) cohesion
   (c) adhesion
   (d) viscosity
Ans: (a)
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