Skip to content

Course home

Sign up

3.2.3a Converging and diverging lenses

EasyMedium
12345678910111213141516171819202122
Question 20

A student is performing an experiment using a thin converging lens to find its focal length. They are provided with:

  • an illuminated object containing a stencil of the capital letter F
  • a converging lens on a holder
  • a screen
  • a laboratory bench with a metre rule
a.

Describe the correct order and alignment of the illuminated object, the lens, and the screen along the bench to perform this experiment.

[2]
b.

The focal length of the lens is approximately 20 cm20\text{ cm}20 cm. Suggest a suitable distance ddd between the illuminated object and the screen so that a sharp image can be focused on the screen, and explain your choice with reference to the focal length fff.

[3]
c.

State two practical difficulties in this experiment that make it hard to obtain an accurate value for the focal length.

[2]
d.

Describe the appearance of the focused image of the capital letter F as seen on the screen by the student.

[2]
Markscheme

3.2.3a Converging and diverging lenses Questions

  1. IGCSE
  2. /Physics
  3. /3.2.3a Converging and diverging lenses

56 exam-style questions on CIE IGCSE Physics 3.2.3a Converging and diverging lenses. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank