Advertisements
Advertisements
Question
Give any two applications of a concave and convex mirror.
Advertisements
Solution
- Concave mirrors:
- Concave mirrors are used while applying make–up or shaving, as they provide a magnified image.
- They are used in torches, search lights, and head lights as they direct the light to a long distance.
- Convex mirrors:
- Convex mirrors are used in vehicles as rearview mirrors because they give an upright image and provide a wider field of view as they are curved outwards.
- They are found in the hallways of various buildings including hospitals, hotels, schools, and stores. They are usually mounted on a wall or ceiling where hallways make sharp turns.
APPEARS IN
RELATED QUESTIONS
With the help of an appropriate ray diagram, state the sign conventions for reflection by a spherical mirror.
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
Briefly describe how you would find the focal length of a concave mirror quickly but approximately
The diagram shows a dish antenna which is used to receive television signals from a satellite. The antenna (signal detector) is fixed in front of the curved dish.
Figure
(a) What is the purpose of the dish?
(b) Should it be concave or convex?
(c) Where should the antenna be positioned to receive the strongest possible signals?
(d) Explain what change you would expect in the signals if a larger dish was used.
To find the focal length of a concave mirror Rahul focuses a distant object with this mirror. The chosen object should be
(1) a tree
(2) a building
(3) a window
(4) the sun
A child is standing in front of a magic mirror. She finds the image of her head bigger, the middle portion of her body of the same size and that of the legs smaller. The following is the order of combinations for the magic mirror from the top.
An object at a distance of 30 cm from a
concave mirror gets its image at the same point. The focal length of the mirror is ______.
Which of the following mirror is used by a dentist to examine a small cavity in a patient’s teeth?
The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?
A student took three concave mirrors of different focal lengths and performed the experiment to see the image formation by placing an object at different distance with these mirrors as shown in the following table.
| Case No. | Object-distance | Focal length |
| I | 45 cm | 20 cm |
| II | 30 cm | 15 cm |
| III | 20 cm | 30 cm |
Now answer the following questions:
(a) List two properties of the image formed in Case I.
(b) In which one of the cases given in the table, the mirror will form real image of same size and why?
(c) Name the type of mirror used by dentists. Given reason why do they use such type of mirrors.
OR
(c) Look at the table and identify the situation (object distance and focal length) which resembles the situation in which concave mirrors are used as shaving mirrors? Draw a ray diagram to show the image formation in this case.
