A student has three converging lenses, A, B and C. The lenses are made from the same type of glass and have the same diameter.
The Table shows information about the lenses.
Table
| Lens | Thickness at the centre in mm\text{mm}mm | Focal length in cm\text{cm}cm |
|---|---|---|
| A | 4 | 40 |
| B | 8 | 20 |
| C | 12 |
Identify which lens, A or B, has the greater power. Give a reason for your answer.
Predict whether the focal length of lens C is greater than or less than 20 cm. Give a reason for your answer.
Describe how the shape of a diverging lens is different from the shape of a converging lens.
State what is meant by the principal focus of a converging lens.
93 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses, covering 5.1.1 Reflection, refraction and total internal reflection, 5.1.2 Specular and diffuse reflection, 5.1.3 Colour of light: absorption and filters, 5.1.4 Lenses: power, focal length and shape, 5.1.5 Ray diagrams for converging and diverging lenses, and 5.1.6 Real and virtual images. Each one has a worked solution and a mark scheme showing where the marks go.