List four characteristics of the image formed by a concave mirror of focal length 40 cm when the object is placed in front of it at a distance of 20 cm from its pole.

Explanation

To solve the problem, we need to determine the characteristics of the image formed by a concave mirror when an object is placed in front of it. Here’s a step-by-step solution:

### Step 1: Identify the given values
- Focal length (f) of the concave mirror = -40 cm (negative because it is a concave mirror)
- Object distance (u) = -20 cm (negative as per the sign convention for mirrors)

### Step 2: Use the mirror formula
The mirror formula is given by:
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