Question

As the distance of an object from a converging mirror decreases ,
the image

Answer 1

the image will increase so it is used as dentist mirror

Answer 2

As the distance of an object from a converging mirror decreases, the image distance from the mirror focus increases.

• Concave mirror is known as converging mirror.
• It converges the incident lights parallel to the principle axis towards it focus.

Suppose,

The focal length of a concave mirror (f) = 20 cm

The object distance = u

The image distance = v

Let, u = 40 cm in first case

In first case,

By applying mirror formula, i.e.,

$\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$

We get,

$\frac{1}{v} + \frac{1}{-40} = \frac{1}{-20}$  [By putting the values with proper sign]

⇒ v = - 40 cm

∴ Distance from the focus of the mirror = 40 cm

In second case,

Suppose, u = 30 cm [u is decreased from the previous one]

∴  $\frac{1}{v} + \frac{1}{-30} = \frac{1}{-20}$

⇒ v = - 60 cm

∴ Distance from the focus of the mirror = 60 cm

So, as the As the distance of an object from a converging mirror decreases, the distance of the object from the focus of the mirror increases.