Refraction and Diffraction _ GCSE Physics

The video tutorial explains the concepts of refraction and diffraction. Refraction occurs when light passes through substances with different densities, causing a change in direction. The tutorial details how to measure angles of incidence and refraction. Diffraction is discussed as the spreading of waves when they pass through a gap, with examples including sound and light. The video also highlights how diffraction enables radio and microwaves to reach areas behind obstacles.

What happens to a light ray when it passes from air into water?

• It slows down and continues in the same direction.

• It speeds up and changes direction.

• It slows down and changes direction.

• It speeds up and continues in the same direction.

What is the relationship between the angle of incidence and the angle of refraction?

• The angle of incidence is always less than the angle of refraction.

• The angle of incidence is always equal to the angle of refraction.

• The angle of incidence is unrelated to the angle of refraction.

• The angle of incidence is always greater than the angle of refraction.

What is diffraction?

• The absorption of waves by a material.

• The reflection of waves off a surface.

• The spreading of waves as they pass through a gap.

• The bending of light as it passes through a lens.

Why can you hear sound through a door even if you are not directly in front of it?

• Sound waves are diffracted through the door.

• Sound waves are reflected by the door.

• Sound waves are refracted through the door.

• Sound waves are absorbed by the door.

How does diffraction help in the transmission of radio waves?

• It allows radio waves to spread out and reach areas behind obstacles.

• It allows radio waves to be absorbed by hills.

• It allows radio waves to be reflected off mountains.

• It allows radio waves to travel in a straight line through obstacles.