Question

Explain using a sketch. 5. A bottle stands (1.5) m in front of a concave mirror which has a (50 ) cm focal length. a. Write down the properties of the image. b. Where should it be placed in order to obtain a magnified image?

Answer 1

Here,we can use mirror formula i.e `1/v +1/u =1/f` to calculate the distance of the image from the mirror.

Given, `u=-1.5 , f=- 50/100`

So, `v= - 3/4 m`

Now, magnification for an image formed in concave lens is given as, `- (v/u) = -(-3/4)/(1.5)=-0.5`

So,the image will be formed at a distance of `0.75 m` from the centre of mirror against the direction of light, real,inverted( see the `-` sign) and with `1/2` the length of the object

Now,in the mirror formula if we put, `u=-2f`,we get magnification=`-1`,so putting the object at a distance of more than twice of focal length will give you magnified real image,on the other hand,putting the object inside the focus i.e `u< f` ,you will get magnified but virtual image.

See below,