Question

Define the magnifying power of a compound microscope when the final image is formed at infinity. Why must both the objective and the eye piece of a compound microscope has short focal length? Explain.

Answer 1

Magnifying power is defined as the angle subtends at the eye by the image to the angle subtended by the object.

m = m₀ × m_e = \(\frac{L}{f_0} \times \frac{D}{f_e}\)

To increase the magnifying power both objective and eye piece must have short focal lengths such as,

m = \(\frac{L}{f_0} \times \frac{D}{f_e}\)