An air bubble inside water. The refractive index of water is 4/3 . At what distance from the air bubble should a point object be placed so as to form a real image at the same distance from the bubble:-

Options

A. 2R
B. 3R
C. 4R
D. The air bubble cannot form a real image

Explanation

To solve the problem of finding the distance from the air bubble where a point object should be placed to form a real image at the same distance from the bubble, we can follow these steps:

### Step 1: Understand the properties of the air bubble in water
An air bubble in water behaves like a diverging lens because air has a lower refractive index compared to water. The refractive index of water is given as \( n = \frac{4}{3} \).

### Step 2: Identify the nature of the image formed by the bubble
Since the air bubble acts as a diverging lens, it will only form virtual images. A diverging lens cannot form real images; it can only create virtual and erect images.

### Step 3: Conclusion based on the properties of the bubble
Since the air bubble cannot form a real image, it is impossible to place a point object at any distance from the bubble to achieve a real image at the same distance from the bubble.

### Final Answer
The answer is that it is not possible to place a point object at any distance from the air bubble to form a real image at the same distance from the bubble.

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