Question

answer the question observe the figure and state the rule for drawing ray diagram

Answer 1

Hi there!

(1) Any incident ray which is parallel to the principal axis passes through the focus.

(2) wavelength : meter :: frequency : sec^-1
  
      because, frequency = c / λ , where c= speed of light (meter per second) and λ = wavelength (meter).
hence the relation would be,

 Wavelength : meter :: Frequency : sec^-1

Hope it helps!!