Question

the focal length of a convex lens is 10cm.if an object is kept at a distance of 20cm in front of the lens the image formed is ​

Answer 1

Answer:

Explanation:

1/10+1/q=1/20

1/q=1/20–2/20=-1/20

q=-20

m=- -20/10=+2

Image is erect, virtual, and twice the size of the object.

Problems like these are solved by using the lens equation: 1/p+1/q=1/f

f is positive for a convex lens and negative for a concave lens.

The magnification is: m=-q/p

Answer 2

Answer:

20cm

Explanation:

1/f=1/u+1/v

1/10=1/20+1/v

1/10-1/20=1/v

2-1/20=1/v

1/20=1/v

V=20cm