Question

Why are there two parallel plane mirrors in a barber shop?
A. Two parallel plane mirrors from infinite images
B. The customer can see the image of the back of his head with the help of this setup.
C. The setup focusses light and helps the barber to cut the hair better.
D. None of the above.

Answer 1

Hint: The plane mirror is a smooth and completely flat surface mirror. If a parallel beam of light is incident on the plane mirror then reflected back it must be parallel. Plane mirrors mainly used to see the reflected objects. Remember the point, The distance of the image formed is equal to the distance of the object from the mirror.

Complete step by step answer:
Commonly plane mirrors used to see ourselves so, it is widely used in the barbershop, salon, and beauty parlor. For the purpose of using a plane mirror in shops to give a better view of hair from the front and back to the customers. A plane mirror always forms a virtual image.
When two plane mirrors are kept parallel to each other then we can see an infinite number of images. Each image is fainter than the previous one when some light is lost in the process of reflection. Then the images become fainter as the distance from the mirror increases.
Usually, we used a plane mirror to see ourselves but in the barbershop, we used two plane mirrors which kept in parallel for the customer’s satisfaction. Through this, we can see the image of hair cut from the front and back to the customer.
The two Parallel plane mirror setups are not used for our work which helps the barber to cut the hair in a better way.

So, the correct answer is “Option B”.

Note: Always, plane mirrors form a virtual image and erect image. Remember, the image is also laterally inverted, which means the left side of the object appears on the right side of the image and the right side of the object appears on the left side of the image.