Q39
4 marksSection Section E

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 distances with these mirrors as shown in the following table.

Table:

Case No.Object-distanceFocal length
I45 cm20 cm
II30 cm15 cm
III20 cm30 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. Give 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.

Light — Reflection and Refraction
Reflection of Light
Official Answer

(a) The image formed in Case I is real and inverted.

(b) In Case II, the mirror will form real image of same size.

(c) The type of mirror used by dentists is a concave mirror. They use such type of mirrors because they provide a large, clear and erect image of the teeth of patients.

concave mirrorreal imageinverted imagesame size

Marking Scheme

  • 14 marks

Hint

Analyze the data given in the table and recall the properties of images formed by a concave mirror.

Quick Oral Answer

The type of mirror used by dentists is a concave mirror. They use such type of mirrors because they provide a large, clear and erect image of the teeth of patients.

Analysis & Explanation

The question requires the student to analyze the data given in the table and answer the questions based on the properties of images formed by a concave mirror.

Common Mistakes

  1. 1Incorrectly identifying the type of mirror used by dentists.

Interesting Facts

Concave mirrors are commonly used in torches, search-lights and vehicles headlights to get powerful parallel beams of light.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2023?

This question carries 4 marks in the CBSE Class 10 Science 2023 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Light — Reflection and Refraction" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Reflection of Light" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2023 paper?

This question appears in Section Section E in the CBSE Class 10 Science 2023 paper.