Question

An object is placed at a distance of 4 centimeters in front of a convex mirror. whose focal length is 5 centimeters. where is the image formed?​

Answer 1

Explanation:

The focal length of mirror is 15 cm . ... 4 cm is placed in front of a concave mirror at a distance of 30 cm. ... in front of a concave lens, the image is formed at the same point.

Answer 2

Explanation:

Object Distance(u) = 4 cm. (negative)

Focal length of the lens (f) = 5 cm.

We know, convex mirror always forms the virtual, upright and diminished.Also, Object distance in the convex mirror is always negative where as Image distance and focal length are positive.

Now, Applying the Mirror's Formula,

1/f = 1/v + 1/u

1/5 = 1/v +1

1/5 = (4-v)/4v

4v = 5(4-v)

4v =20-5v

9v = 20

v = 20 / 9