Question

Please answer the question provided in the attachment.

Answer 1

As
h1=4cm
u=-20cm
f=-10cm
Apply lens formula
1/f=1/v-1/u
v=-20/3
image will be virtual
as m=h2/h1=v/u
h2=4/3
means smaller than size of object(dimnished) and erect

 

Answer 2

For diagrams, see your book for ray diagrams for image formation in convex lens.
1. Virtual, erect, magnified image will be formed when object is placed between          focus and optical centre.
2. Real and inverted image will be formed when the object is placed beyond focus.(between focus and infinity)

Second Answer:
u = -20 cm
f = -10 cm
v = ?

$\frac{1}{v} - \frac{1}{u} = \frac{1}{f} \\ \\ \frac{1}{v} = \frac{1}{f} + \frac{1}{u}\\ \\ \frac{1}{v}=\frac{1}{-10} + \frac{1}{-20}\\ \\ \frac{1}{v} = \frac{-2-1}{20}= \frac{-3}{20}\\ \\v= \frac{-20}{3}$

So a virtual and erect image will be formed at $\frac{-20}{3}$cm from lens or $\frac{20}{3}$ cm in front of the lens.