An object is placed at a distance of 30 cm from a convex lens of focal length 20 cm. Find the position of the image.

To find the position of the image formed by a convex lens, we can use the lens formula:

1/f = 1/v - 1/u

Where: f = focal length of the lens v = distance of the image from the lens u = distance of the object from the lens

Given: f = 20 cm u = -30 cm (negative sign indicates that the object is placed on the same side as the incident light)

Substituting the given values into the lens formula, we have:

1/20 = 1/v - 1/-30

Simplifying the equation, we get:

1/20 = 1/v + 1/30

To solve for v, we can find the common denominator:

1/20 = (3 + 2)/60

1/20 = 5/60

Now, we can equate the numerators:

1 = 5v/60

Cross-multiplying, we have:

60 = 5v

Dividing both sides by 5, we get:

v = 12 cm

Therefore, the position of the image formed by the convex lens is 12 cm from the lens.