Q4
1 markVery Short AnswerSection A

What is the nature of the image formed by a concave mirror if the magnification produced by the mirror is + 3 ?

Light — Reflection and Refraction
Image Formation by Spherical Mirrors
Official Answer

The nature of the image is virtual and erect. Additionally, since the magnitude of magnification is 3 (which is greater than 1), the image is enlarged.

virtualerectenlargedmagnified

Marking Scheme

  • 1Identifying the image as virtual and erect based on the positive sign. (0.5 marks)
  • 2Identifying the image as enlarged based on the magnitude being greater than 1. (0.5 marks)

Hint

A positive magnification sign always means the image is erect (and virtual for mirrors).

Quick Oral Answer

The image is virtual, erect, and enlarged. The '+' sign tells us it's erect/virtual, and the '3' tells us it's three times the size of the object.

Analysis & Explanation

In the context of spherical mirrors, magnification (mm) carries two pieces of information: the sign and the magnitude. A positive sign signifies that the image is formed above the principal axis (erect), which for a single mirror system implies it is a virtual image. A magnitude greater than 1 (∣m∣>1|m| > 1) indicates that the image is magnified or enlarged compared to the object. According to the NCERT Table 9.1, the only case where a concave mirror produces a virtual and erect image is when the object is between P and F, and that image is always enlarged.

Common Mistakes

  1. 1Thinking a positive sign means a real image.
  2. 2Ignoring the magnitude and only describing the nature as virtual/erect.

Interesting Facts

Concave mirrors are the only spherical mirrors that can produce both real and virtual images, as well as magnified and diminished images.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2010?

This question carries 1 mark in the CBSE Class 10 Science 2010 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 "Image Formation by Spherical Mirrors" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2010 paper?

This is a Very Short Answer question from Section A in the CBSE Class 10 Science 2010 paper.