We wish to obtain an erect image of an object by using a concave mirror of focal length 10 cm.
What should be the distance of the object from the concave mirror ?
Is the image real or virtual ?
Is the image larger or smaller than the object ?

Answer

To solve the problem step by step, we can follow these instructions:

### Step 1: Understand the properties of a concave mirror
A concave mirror can produce both real and virtual images depending on the position of the object. When the object is placed between the focus (F) and the mirror's pole (P), the image formed is virtual, erect, and magnified.

### Step 2: Identify the focal length
The focal length (f) of the concave mirror is given as 10 cm. Therefore, the focus (F) is located at 10 cm from the mirror.

### Step 3: Determine the position of the object
To obtain an erect image, the object must be placed between the focus (F) and the pole (P) of the mirror. Since the focal length is 10 cm, the object must be placed at a distance less than 10 cm from the mirror.

### Step 4: Conclusion about the distance of the object
Thus, the distance of the object from the concave mirror should be less than 10 cm.

### Step 5: Determine the nature of the image
Since the object is placed between the focus and the mirror, the image formed will be virtual.

### Step 6: Determine the size of the image
The image formed in this case will be larger than the object, as it is magnified.

### Final Summary:
1. The distance of the object from the concave mirror should be less than 10 cm.
2. The image formed is virtual.
3. The image is larger than the object.

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