Question

“The linear magnification produced by a spherical mirror is +3.”Based on this statement answer the following questions:
(a) What is the type of mirror?
(b) Where is the object located?
(c) List two properties of the image formed (other than the size/magnification).

Answer 1

Step 1: Understand the meaning of magnification
Magnification (M) is defined as the ratio of the height of the image to the height of the object:
M = height of image / height of object
- If M is positive, the image is erect and virtual.
- If M is negative, the image is inverted and real.

Given: The magnification is +3.
This means the image is 3 times the size of the object and it is erect and virtual.

Step 2: Determine the type of mirror
- Only a concave mirror can produce a virtual and magnified image.
- A convex mirror always produces virtual, erect, but diminished images.
Hence, the mirror must be a concave mirror.

Step 3: Determine the position of the object
For a concave mirror to produce a virtual, erect, and magnified image, the object must be placed between the pole (P) and the focus (F) of the mirror.

Step 4: Properties of the image (other than magnification)
1. The image is virtual – it cannot be captured on a screen.
2. The image is erect – it is upright as compared to the object.

Final Answers:
(a) Concave mirror
(b) Between the pole and the focus of the mirror
(c) Image is virtual and erect