A corrective eyepiece for a telescope uses a diverging lens with a focal length of -12.5 cm.
Calculate the power of this lens in dioptres.
Use the equation:
power of a lens=1focal length in metres \text{power of a lens} = \frac{1}{\text{focal length in metres}} power of a lens=focal length in metres124 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses (physics only). Each one has a worked solution and a mark scheme showing where the marks go.