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 30cm from the mirror where is the object placed?find the position of the image if the object is now moved 20cm towards the mirror. What is the nature of the image obtained .draw a ray diagram

Answer 1

In the ray diagram that I have drawn the the image will be virtual and erect . Since, I have tried to answer the question in just one page thats why the ray diagram cannot be completed . Therefore the rays will intersect each other .
Thank you

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.