Question

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

Answer 1

★Solution :-

As per the given data ,

• Object Distance = - 4 cm

Object distance is always negative as distance is measured from the pole of the mirror

• Focal length = + 5 cm

Focal length of a convex mirror is positive

We need to find the distance of the image from the pole of the mirror in order to do that simply use mirror formula ,

As per mirror formula ,

➽ 1 / f = 1 / v + 1 / u

On rearranging ,

➝ 1 / v = 1 / f - 1 / u

➝ 1 / v = 1 / 5 - 1 / (-4)

➝ 1 / v = 1 / 5 + 1 / 4

➝ 1 / v = 4 - 5 / 20

➝ 1 / v = - 1 / 20

➝ v = - 20 cm

The image is formed at a distance of 20 cm from the pole of the mirror on the same side as that of the object

★ Know more :-

♣ Mirror :-

Magnification

$\bigstar\boxed{\mathtt{ m = - \dfrac{v }{u} = \dfrac{h_i }{h_o}}}$

♣ Lens :-

Lens formula ,

$\bigstar\boxed{\mathtt{ \dfrac{1 }{f } = \dfrac{1}{v }- \dfrac{1}{u }}}$

Magnification ,

$\bigstar\boxed{\mathtt{ m = \dfrac{v }{u} = \dfrac{h_i }{h_o}}}$

here ,

1. v = image distance
2. u = object distance
3. f = focal length
4. m = magnification
5. hi = height of image
6. ho = height of object