Lakhmir Singh and Manjit Kaur Solutions for Chapter: Refraction of Light, Exercise 26: Very Short Answer Type Questions

The lens $A$ produces a magnification of, $-0.6$ whereas lens $B$ produces a magnification of $+0.6$.

What is the nature of lens $A$?
(Choose from: diverging / converging)

The lens $A$ produces a magnification of, $-0.6$ whereas lens $B$ produces a magnification of $+0.6$.

What is the nature of lens $B$? 

(Choose from: Convex / Concave / Plano-Convex)

A $50 \mathrm{cm}$ tall object is at a very large distance from a diverging lens. A virtual, erect and diminished image of the object is formed at a distance of $20 \mathrm{cm}$ in front of the lens. How much is the focal length of the lens?