Q.21)-What principle/law explains the working of the hydraulic brakes in automobiles?
- Bernoulli's law
- Posieulle's principle
- Pascal's law
- Archimedes' principle
Q.22)-An oil drop spreads over water because
- Oil is lighter than water
- Oil is more viscous
- Oil does not mix with water
- Surface tension of oil is much smaller than that of water
Q.23)-A fountain pen works on the principle of
- Flow of liquids from higher to lower potential
- Capillary action
- Bernoulli's principle
- Viscosity of liquids
Q.24)-A falling drop of rain water acquires the spherical shape due to
- Viscosity
- Surface tension
- Atmospheric pressure
- Gravitational force
Q.25)-The weakest of all fundamental forces is
- Gravitational force
- Electrosatic force
- Magnetic force
- Nuclear force
Q.26)-The modulus of rigidity is the ratio of
- Longitudinal stress to longitudinal strain
- Volume stress to volume strain
- Shearing stress to shearing strain
- Tensile stress to tensile strain
Q.27)-A spherical ball made of steel when dropped in mercury container will
- Sink in mercury
- Will be on the surface of mercury
- Will be partly immersed
- Will dissolve in mercury
Q.28)-Damp clothes are dried in spin dryers by the action of
- Centripetal force
- Centrifugal force
- Central forces
- None central forces
Q.29)-Which of the following is a result of surface tension?
- Gravitational pull
- Viscosity
- Capilllary action
- Radiation
Q.30)-The wall of a dam is broader at the base
- Because streamlining is required
- To withstand pressure that increases with depth
- To withstand pressure that increases in a horizontal plane
- To withstand pressure that is increased with atmosphere pressure