11.

The diagram below shows a lever in use: 


 

i) To which class of lever does it belong?

ii) If FA = 40 cm, AB = 60 cm, then find the mechanical advantage (M.A. ) and velocity ratio (V.R.) of an ideal machine?

i) What is meant by an ideal machine?

ii) Write a relationship between the mechanical advantage (M.A.) and velocity ratio (V.R.) of an ideal machine.

In the diagram below, PQ is a ray of light incident on a rectangular glass block.

i) Copy the diagram and complete the path of the ray of light through the block. In your diagram, mark the angle of incidence by letter ‘I’ and the angle of emergence by the letter ‘e’. 

ii) How are the angles ‘I’ and ‘e’ related to each other? [2] 

How is the refractive index of a medium related to its real depth and apparent depth? 

State the laws of refraction of light? 

Write a relation between the angle of incidence (i), angle of emergence (e), angle of prism (A) and angle of deviation (d) for a ray of light passing through an equilateral prism.

When does a ray of light falling on a lens pass through it undeviated? 

Which lens can produce a real and inverted image of an object?

Which characteristic property of light is responsible for the blue colour of the sky?