Differentiate between resonance and forced vibrations. 

The wavelength of waves produced on the surface of water is 20 cm. If the wave velocity is 24 m/s, calculate:

1. The number of waves produced in one second and,
2. The time required to produce one wave. 

i) State the purpose of a fuse in an electric circuit. Name the material used for making a fuse wire.

ii) Mention two factors on which the internal resistance of a cell depends.

Draw a labelled diagram to show the various components of a step-down transformer. 

State the main difference between a step-up and step-down transformer. 

In winter, the weather forecast for a certain day was ‘severe frost’. A wise farmer watered his fields the night before to prevent frost damage to his crops. Why did he water his fields? 

10125 J of heat energy boils off 4.5 g of water at 100^oC to steam at 100^o C. Find the specific latent heat of steam. 

18.

Define the term work function of a metal. 

Mention two common properties of gamma radiations and visible light. 

A ball of mass 0.20 kg is thrown vertically upwards with an initial velocity of 20 m/s. Calculate the maximum potential energy it gains as it goes up.