A 4.5 cm needle is placed 12 cm away from a convex mirror of focal lenght 15cm. Give the location of the image and draw aray diagram
Answers
Explanation:
sorry I tried my level best
nature of image
1. virtual image
2. erected image
3. it is formed back side of object
4. enlarged image
Answer:
Given: Height of the needle, H_{1}H
1
= 4.5cm.
Object distance, u= −12cm.
The focal length of the convex mirror, f=15cm.
Image distance, v The value of v can be obtained using the mirror formula.
v/1 + u/1 = f/1
1/v + 1/-12 = 1/15
v/1= 12/1 + 151
v1=609
∴ v ≈ 6.7cm
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.
m = h′/h = −v/u
h′ =
12
6.7∗4.5
⇒ h′ = +2.5cm
So, m = \frac{2.5}{4.5}
4.5
2.5
m = 0.56
The height of the image is 2.5cm. The positive sign indicates that the image is erect, virtual, and diminished. If the needle is moved farther from the mirror, the size of the image will reduce gradually.