Question

A 4.5 cm needle is placed 12 cm away from a convex
mirror of focal length 15 cm. Give the location of the
image and its magnification.
PLz Tell​

Answer 1

Answer:

Hey buddy's which question you are asking i am sure its from class 10th Chapter 1 science questions ....

here is your answers Magnification is 0.56 and location is 6.7 cm away from mirror ...

Explanation:

Height of the needle, h1 = 4.5 cm

Object distance, u = −12 cm

Focal length of the convex mirror, f = 15 cm

Image distance = v

The value of v can be obtained using the mirror formula

1/u + 1/v = 1/f

1/v = 1/f – 1/u

Now,

putting u = –12 cm and f = +15cm , we get

1/v = 1/15 – 1/-12 = 4+5/60 = 9/60

v = 60/9 = 6.7 cm

Hence, the image of the needle is 6.7 cm away from the mirror. Also, it is on the other side of the mirror.

The image size is given by the magnification formula:

image is formed 6.7 CM behind the convex mirror. it must be virtual and erect.

if h2 is size of image , then m = h2/h1 = -v/u

or,

m = h2/h1 = –(6.7)/–12 = 0.558

h2 = 0.558

h1 = 0.558 * 4.5 = 2.5 cm

Hence magnification m = h2/h1 = 2.5/4.5 = 0.56

It is a verified answer and it is really correct ....

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Thankuuuu