Question

the image of an object formed by a mirror is real inverted and is of magnification -1 if the image is at the distance of 30 cm from the mirror where is the object placed find the position of the image if the object is now moved 20cm towards of the mirror what is the nature of the image of 10 justify your answer with the help of a diagram

Answer 1

When the object is at Infinity and image is formed at F(Principle Focus), then the image is the brightest/of greatest intensity. As the object is moved forward, that is, near the convex lens, the image brightness/intensity goes on decreasing. ... How does the position of an object or ...

Answer 2

Answer:

+ 30 cm

Explanation:

Given :

Magnification = - 1

Image distance = 30 cm

We know

m = - v / u

- 1 = 30 / u

u = - 30 cm

Now we have ,

1 / f = 1 / v + 1 / u

1 /  f = 1 / - 30 - 1 / 30

f = - 15 cm

When object moved 20 cm

u' = - 30 + 20 = - 10 cm

We have f = - 15 cm

We have to find new image distance v'

Again ,

1 / f = 1 / v' + 1 / u'

- 1 / 15 = 1 / v' - 1 / 10

1 / v' = 1 / 30

v' = 30.

Nature of image as :

Virtual

Erect

Magnified.