KS1 (Age 5-7)KS2 (Age 7-11)11 Plus (Age 7-11)KS3 (Age 11-14)GCSE (Age 14-17)PSHE A.I.ESL Spanish Specialist Games

Need help with Light - Lenses 01? Ask our AI Tutor!

AI Tutor - Lucy

Connecting with Tutor...

Please wait while we establish connection

Hi! I'm Lucy, your AI tutor. How can I help you with Light - Lenses 01 today?

now

A converging lens would be a good choice to use for the purposes of magnification.

Light - Lenses 01

Lenses bend light to form images. In this GCSE Physics quiz you’ll explore converging and diverging lenses, focal length and how lenses correct vision.

Explore the Topic →

(quiz starts below)

Fascinating Fact:

The principal focus of a diverging lens is the point from which rays parallel to the principal axis appear to come after refraction.

In GCSE Physics, lenses are used to show how refraction can make light rays converge or diverge. You learn how to draw ray diagrams, find focal lengths, and predict the size and position of images.

Key Terms

Principal axis: The straight line that passes through the centre of the lens and is used as a reference for ray diagrams.
Principal focus: The point where rays parallel to the principal axis either meet (converging lens) or appear to come from (diverging lens).
Focal length: The distance between the centre of the lens and its principal focus, usually measured in metres or centimetres.

Frequently Asked Questions (Click to see answers)

What is the difference between a converging and diverging lens?

A converging lens is thicker in the middle and brings parallel rays together at a focus. A diverging lens is thinner in the middle and spreads parallel rays apart.

How do you find the focal length of a lens in GCSE Physics?

In GCSE Physics, you can find focal length by using a distant object and moving a screen until a sharp image forms, or by using 1/f = 1/u + 1/v with measured distances.

How do lenses form real and virtual images?

Lenses form real images when refracted rays actually meet on a screen. Virtual images occur when rays only appear to come from a point, such as in a magnifying glass or diverging lens.

Try These Related Quizzes

1 .

What is refraction?

The manipulation of light to form bright and dark spots by passing it through a narrow slit

The change in direction of light as it passes from one medium to another

The ability of light to spread out to fill a room

The ability of light to penetrate solid objects

As light travels from one medium to another, it either speeds up or slows down. This change in speed means that any light entering at an angle will bend due to one side of the beam hitting the medium before the other

2 .

How does a lens work?

It forms an image by refracting light

It forms an image by diffracting light

It forms an image by diffusing light

It takes a picture with a digital camera and tags it on Facebook for you to see

Because it has a curved surface, most of the light entering the lens hits at an angle and is therefore refracted

3 .

Consider a convex lens - parallel rays of light are brought to a focus at which point?

Secondary focus

Primary focus

Principal focus

Focal place

The principal focus or focal point is the point at which a lens focusses the light which is incident upon it

4 .

What is the distance from the lens to the principal focus called?

Focal width

Focal height

Focal length

Focal point

Less curved lenses have longer focal lengths

5 .

Which formula correctly states how refractive index is related to the angles of incidence and refraction?

refractive index = ^{sin i}⁄_{sin r}

refractive index = ^{sin r}⁄_{sin i}

refractive index = ^{sin i}⁄_{2 sin r}

refractive index = ^{2 sin i}⁄_{sin r}

It is a ratio and therefore has no units

6 .

What does i represent in the above equation?

The normal

The angle of refraction

The angle of incidence

The refractive index

In optics, the incoming light hitting any surface is called the incident light

7 .

What does r represent in the above equation?

The angle of incidence

The angle of refraction

The normal

The refractive index

In addition, on a ray diagram, the normal line is a line drawn at the point at which the light beam enters the material and is drawn perpendicular to the surface of the material

8 .

The nature of an image produced by a lens is defined by which attributes?

The relative size of the image

Whether the image is upright or inverted relative to the object

Whether the image is real or virtual

All of the above

Make sure that you know how to describe images from lenses and other optical devices

9 .

Which type of lens would be a good choice to use for the purposes of magnification?

Diverging lens

A concave lens

A converging lens

Bi concave lens

Concave lenses cause rays of light passing through them to diverge. The image is always virtual and diminished

10 .

What is the refractive index of a medium when light is incident upon it at 45^o to the normal and the angle of the refraction is 30^o from the normal?

1.1

1.2

1.3

1.4

You need to find the sine of each angle and then you can substitute the values into the refractive index equation

You can find more about this topic by visiting BBC Bitesize - Lenses

Author: Martin Moore