Question

3. List any three causes of soil
pollution.
4. Write one difference between sand, clay & salt.
5. With the help of diagram explain about virtual image.
6. Describe about concave & convex lens with figure.​

Answer 1

3)

• increased salt content
• compacting
• soil degradation

6) concave lens

concave lens is a type of diverging lens. it is thinner in middle and thicker in edges. it is drawn as a vertical line with inward facing arrow to indicate the shape of lens.

convex lens

convex convex lens is a type of converging lens it is thinner at the ends and thicker at the middle. this this lens is also called as biconvex lens.