same lens is 1 What is the power or combinahon i en of a needle in front of - find the Long Answer Type Questions 29. (a) What do you understand by the power of a lens ? Name one factor on which the power of a lens depends is the unit of power of a lens ? Define the unit of power of a lens. combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40.com d a diverging lens of focal length 59 cm. Find the power and focal length of the combination 2 and (in - 4 D respectively. What is the nature and focal 20 )