Light

Question 1

What happens when rays hit a plane mirror?

Answer 1

They are reflected

Question 2

What are the characteristics of an image formed by a plane mirror

Answer 2

• same size as the object
• inverted
• virtual

Question 3

When light is reflected how do angle i and r compare?

Answer 3

angle of incidence=angle of reflection

Question 4

How are the angles of incidence and reflection measured

Answer 4

relative to the normal

Question 5

What is a virtual image?

Answer 5

An image produced on the same side of the lens as the object and that cannot be projected

Question 6

What is a virtual image

Answer 6

An image produced on the opposite side of the lens

and that can be projected

Question 7

What kind of image is produced by a plane mirror

Answer 7

A virtual image

Question 8

What is refraction?

Answer 8

Refraction is the change in speed, of a wave crossing a boundary between two media, resulting in change of direction

Question 9

What property of a wave is not changed by refraction?

Answer 9

The frequency

Question 10

What is the critical angle?

Answer 10

The angle of incidence which produces an angle of refraction at 90°

Question 11

What is internal reflection ?

Answer 11

When light reaches aboundary and it reflectd back into the medium it came from

Question 12

What is total internal refraction ?

Answer 12

When a ray of light is fully reflected into the medium it came from, when reaching boundary between media.

Question 13

When does total internal refkection happen?

Answer 13

When the angle of incidence is greater than the critical angle

Question 14

Define refractive index

Answer 14

The ration of the speed of light in a vacuum compared to the speed of light in any medium.

Question 15

Give the equation for the refractive index

Answer 15

refractive index= sin(i)/sin(r)

refractive index=1/sin(i)

Question 16

When light passes through a converging lens ____

Answer 16

The light rays bend towrads the normal, and meet at a focal point

Question 17

What is the principla focus of a lens ?

Answer 17

A focal point before the convex lens, from which the light rays seem to appear from, or the focal point after concave lens where all the rays meet

Question 18

How can lenses act as magnifying glasses?

Answer 18

By producing an enlarged, virtual image

Question 19

How does wavelenght affect refraction?

Answer 19

Shorter wavelenght - waves refract more

Question 20

What happens when a white light is shone through a prism

Answer 20

It seperates into a spectrim of all its coloured light components

Question 21

Why is white light seperated by a prism

Answer 21

Each differnt coloured light wave has a different wavelength. The greater the wavelength, the slower the speed in glass and the greater the refractive index

Question 22

List, in the correct order, the colour
spectrum produced by the dispersion of
white light

Answer 22

red, orange, yellow, green, blue, indigo, violet

Question 23

What is monochromatic light?

Answer 23

Light of a single frequency