Q12
3 marksShort AnswerSection A

The image of an object formed by a mirror is real, inverted and is of magnification – 1. If the image is at a distance of 40 cm from the mirror, where is the object placed? Where would the image be if the object is moved 20 cm towards the mirror? State reason and also draw ray diagram for the new position of the object to justify your answer.

The Human Eye and the Colourful World
The Human Eye and the Colourful World
Official Answer

The mirror is a plane mirror. The image is formed at a distance of 40 cm from the mirror. The object is placed at a distance of 40 cm from the mirror. When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror. The new position of the image will be 20 cm from the mirror. The ray diagram for the new position of the object is shown below.

plane mirrorimageobjectdistance

Marking Scheme

  • 1The mirror is a plane mirror.
  • 2The image is formed at a distance of 40 cm from the mirror.
  • 3The object is placed at a distance of 40 cm from the mirror.
  • 4When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror.
  • 5The new position of the image will be 20 cm from the mirror.

Hint

The mirror is a plane mirror. The image is formed at a distance of 40 cm from the mirror. The object is placed at a distance of 40 cm from the mirror. When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror. The new position of the image will be 20 cm from the mirror.

Quick Oral Answer

The mirror is a plane mirror. The image is formed at a distance of 40 cm from the mirror. The object is placed at a distance of 40 cm from the mirror. When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror. The new position of the image will be 20 cm from the mirror.

Analysis & Explanation

The mirror is a plane mirror. The image is formed at a distance of 40 cm from the mirror. The object is placed at a distance of 40 cm from the mirror. When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror. The new position of the image will be 20 cm from the mirror.

Common Mistakes

  1. 1The mirror is a concave mirror.
  2. 2The image is formed at a distance of 20 cm from the mirror.
  3. 3The object is placed at a distance of 20 cm from the mirror.
  4. 4When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror, but the new position of the image will be 40 cm from the mirror.

Interesting Facts

The mirror is a plane mirror.

The image is formed at a distance of 40 cm from the mirror.

The object is placed at a distance of 40 cm from the mirror.

When the object is moved 20 cm towards the mirror, the image will also move 20 cm towards the mirror.

The new position of the image will be 20 cm from the mirror.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2016?

This question carries 3 marks in the CBSE Class 10 Science 2016 examination.

Which chapter does this question come from in Science?

This question is from the chapter "The Human Eye and the Colourful World" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "The Human Eye and the Colourful World" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2016 paper?

This is a Short Answer question from Section A in the CBSE Class 10 Science 2016 paper.