Question

A convex mirror used for rear-view on a car has a radius of curvature of 5 m. If a bus

is located at 10 m from this mirror. Find the position, nature and size of the image.​

Answer 1

Solution :

As per the given data ,

• Radius of curvature(R) = 5 m

• Image distance (u) = - 10 cm ( distances are always measured from the pole of the mirror )

We know that ,

➨ f = R / 2

➨ f = 5 / 2

➨ f = +  2.5 m ( convex mirror )

Now ,

As per mirror  formula ,

➨ 1 / f = 1 / v + 1 / u

here ,

• f = focal length
• u = object distance
• v = image distance

➨ 1 / v = 1 / f - 1 / u

➨ 1 / v = 1 / 2.5 + 1 / 10

➨ 1 / v = 4 + 1  / 10

➨ 1 / v = 5 / 10

➨ v = 10 / 5

➨ v = 2 m

The image is formed at a distance of 2m behind the mirror

Magnification ,

➨ m = - v / u = hi / ho

➨ m = - 2 / - 10

➨ m = + 1 / 5

The image formed is diminished , erect and virtual