PHYSICS- F2/3

A small drop of oil has a volume of 5 x 10^-8m³. When it is put on a surface of some clean water, it forms a circular film of 0.1m² in area. What is the size of a molecule of oil

• 5 x 10^-8m

• 5 x 10^-7m

• 5 x 10^-9m

• 5 x 10⁹m

A body weighs 600N on the surface of the earth and 450N on the surface of another planet. Calculate the value of g in that planet (g on the earth = 10 N/Kg)

• 0.13 N/kg

• 1.67 N/kg

• 2 N/kg

• 7.5 N/kg

How does temperature rise and impurities affect the surface tension of water

• Temperature change and impurities lower the surface tension of water

• Temperature rise and impurities raise the surface tension of water

• Temperature rise and impurities lower the surface tension of water

• ll the above

Explain the reason why a person moving from lowland to highland is likely to suffer a nose bleeding

• The external pressure (atmospheric) is higher than the internal pressure therefore the capillaries break

• The external pressure (atmospheric) is lower than the internal pressure therefore the capillaries break

• The internal pressure is lower than the external pressure therefore the capillaries break

• none of the above

Distinguish between the three states of matter in terms of particle spacing and kinetics

• Solid – particles very close, hence high kinetic energy

  Liquids – particles fairly free, moderate kinetic energy

  Gases – particles very free, low kinetic energy

• Solid – particles very close, hence high kinetic energy

  Liquids – particles fairly free, moderate kinetic energy

  Gases – particles very free, high kinetic energy

• Solid – particles very close, hence low kinetic energy

  Liquids – particles fairly free, moderate kinetic energy

  Gases – particles very free, high kinetic energy

• Solid – particles very close, hence low kinetic energy

  Liquids – particles fairly free, moderate kinetic energy

  Gases – particles very free, low kinetic energy

Explain why the blades of a panga feels colder than the wooden handle when touched with a finger after exposure to low temperatures

• The metal blade conducts heat to the hand but the wood cannot

• The metal blade conducts heat from the hand but the wood cannot

• The metal blade conducts cold to the hand but the wood cannot

• all the above

State the basic law of magnetism

• unlike charges attract while like charges attract

• unlike terms attract while like terms attract

• like poles attract while unlike poles repel

• Unlike poles attract while like poles repel

Explain the reason why a freely suspended bar magnet comes to rest pointing in the N – S direction

• This is due to the influence of the Earth’s magnetic field

• This is due to the influence of the magnets' magnetic field

• because like poles repel while unlike attract

• all the above

Explain why repulsion is the only sure test for magnetism

• Repulsion only occurs between 2 like poles

• Repulsion only occurs between 2 like poles but attraction may occur between 2 unlike poles

• Repulsion only occurs between 2 like poles but attraction may occur between 2 unlike poles or between a magnet and a magnetic materials

• Repulsion only occurs between 2 like poles but attraction may occur between 2 unlike poles or between a magnet and a demagnetised magnetic materials

Explain why the core is made up of iron and not steel

• Iron is a soft magnetic material it can easily acquire magnetism and can easily lose magnetism.

• steel is a hard magnetic material it can easily acquire magnetism and can retain the magnetism.

• Iron is a hard magnetic material when it gains magnetism its hard to lose it.

• none of the above