Q.41)-Materials for rain proof coats and tents owe their water proof poperties to
  • Surface tension
  • Viscosity
  • Specific gravity
  • Elasticity
Q.42)-When two ice cubes are pressed together they join to form one cube. Which one of the following helps to hold them together?
  • Hydrogen bond formation
  • Vander waals forces
  • Covalent attraction
  • Dipole interaction
Q.43)-When a piece of stone is immersed in water it displaces water of equal
  • Density
  • Specific gravity
  • Mass
  • Volume
Q.44)-The minimum number of forces to keep a particle in equllibrium is
  • 1
  • 2
  • 3
  • 4
Q.45)-Purity of a metal can be determined with the help of
  • Pascal's law
  • Boyle's law
  • Archimedes priciple
  • Conservation of mass principle
Q.46)-In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. The unit of force in this system will be equivalent to
  • 0.1 N
  • 1 N
  • 10 N
  • 100 N
Q.47)-The weight of a body at the centre of earth is
  • Half the weight at the surface
  • Zero
  • Twice the weight at the surface
  • Infinite
Q.48)-On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because
  • Mercury is a metal
  • Density of mercury is greater than that of water
  • Cohesion of mercury is greater than its adhesion with glass
  • Cohesion of water is greater than its adhesion with glass.
Q.49)-Name the process by which bubbles from liquid are formed?
  • Effervescence
  • Surface tension
  • Surface energy
  • Degasification
Q.50)-The wasing machine works on the principle of
  • Dialysis
  • Diffusion
  • Reverse osomosis
  • Centrifugation