A cargo ship is loaded into sea water to maximum capacity. What will happen if this ship is moved to river water? Give a reason for your answer?
A body of mass 100 g is floating in water. What will be it’s apparent weight? Justify your answer.
The diagram given below shows an object O and its image I. Copy the diagram and draw suitable rays to locate the lens and its focus. Name the type if lens in this case.
i) State Snell’s law.
ii) Calculate the velocity of light in a glass block of refractive index 1.5. ( Velocity of light in air = 3 x 108 m/s.
i) What is an optical fibre?
ii) Give one practical use of an optical fibre.
i) An optical fibre is a device based on total internal reflection by which light signal can be sent from one place to the other with negligible loss of energy.
ii) It is used mainly in long distance communication of light signals and in testing the internal parts og human body.
i) Give one difference between a chemical change and nuclear change.
ii) How is a cathode ray tube used to convert an electrical signal into a visual signal?