Plane Mirror - Image Formation - UNSOLVED PRACTICE SET

Q7. List all the characteristics of the image formed by a plane mirror. Which of these make it a 'virtual' image?

Q8. A candle is placed 15 cm in front of a plane mirror. Where is the image formed? What is the size of the image compared to the candle?

Q9. Explain why the word 'AMBULANCE' is written in reverse on the front of ambulances in India. What happens when this is seen in a rear-view mirror?

Q10. A person walks toward a plane mirror at 2 m/s. At what speed does the image appear to move toward the person? Explain.

Q11. Prove geometrically (or explain with a diagram) that the image in a plane mirror is as far behind the mirror as the object is in front of it.

Q12. Why is the image in a plane mirror called 'virtual'? Can it be obtained on a screen? How does it differ from a 'real' image?

Q13. Describe in detail the process of image formation in a plane mirror. Your answer must include:
(a) how rays from a point object reflect from the mirror, (b) why the image appears to be behind the mirror,
(c) all five characteristics of the image,
(d) what 'virtual' means in the context of image formation, and
(e) what changes if the object is moved farther from the mirror. 

Q14. A student 1.6 m tall stands in front of a full-length mirror in a changing room.
(a) What is the minimum length of mirror needed for her to see her full reflection? Show the reasoning with a diagram or geometric explanation.
(b) Does it matter how far she stands from the mirror? Explain.
(c) If the mirror is only 0.6 m tall but positioned at eye level, what part of her body can she NOT see?
(d) Why are mirrors in Indian hotel lobbies often floor-to-ceiling?

Q15. Analyse what happens when two plane mirrors face each other (as in a barber's shop in India, where mirrors on both walls create an infinite series of images).
(a) How many images are formed when two mirrors are parallel?
(b) Explain why each successive image is slightly dimmer.
(c) If the mirrors are at 60° to each other, how many images are formed? Use the formula n = (360/θ) − 1.
(d) What practical use do barbers make of this arrangement?
(e) Explain the concept of 'field of view' of a mirror — why can you only see part of the room in a small mirror?

Q16. A boy stands 4.5 m from a plane mirror.
(a) How far is the image from the mirror?
(b) How far is the boy from his own image?
(c) He walks 1.5 m toward the mirror — now how far is he from his image?
(d) At what speed must he walk toward the mirror so that his image approaches him at 3 m/s? 

Q17. An object 6 cm tall is placed 20 cm in front of a plane mirror.
(a) Find the position of the image.
(b) Find the size of the image.
(c) Calculate the magnification.
(d) Is the image real or virtual? Erect or inverted?
(e) If the object is moved to 35 cm from the mirror, what changes and what stays the same?

Q18. A room has two plane mirrors on opposite walls, 3 m apart. A candle is placed 1 m from one mirror.
(a) Find the position of the first image in the nearer mirror (Mirror 1).
(b) This image acts as an object for Mirror 2 — find the first image in Mirror 2.
(c) That image in Mirror 2 acts as an object for Mirror 1 — find the second image in Mirror 1.
(d) Why do the images get progressively dimmer in a real barber shop?
(e) Theoretically, how many images are formed?