The gravitational force between two masses kept at a certain distance is p N. The same two masses are now kept in water and the distance between them is kept same. The gravitational force between these two masses in water is q N. Then

Options

A. `p = q`
B. `p lt q`
C. `p gt q`
D. None of these

Explanation

To solve the problem, we need to analyze the gravitational force between two masses when they are in air and when they are submerged in water.

### Step-by-Step Solution:

1. **Understanding Gravitational Force**:
The gravitational force \( F \) between two masses \( M_1 \) and \( M_2 \) separated by a distance \( R \) is given by the formula:
\[ F = \frac{G \cdot M_1 \cdot M_2}{R^2} \]
where \( G \) is the universal gravitational constant.

2. **Given Information**:
- When the two masses are in air, the gravitational force is \( P \) N.
- When the same masses are submerged in water, the gravitational force is \( Q \) N.
- The distance \( R \) between the masses remains unchanged.

3. **Effect of Medium on Gravitational Force**:
It is important to note that gravitational force is independent of the medium in which the masses are placed. This means that whether the masses are in air, water, or any other medium, the gravitational force between them remains the same as long as the masses and the distance between them do not change.

4. **Conclusion**:
Since the gravitational force does not depend on the medium, we can conclude that:
\[ Q = P \]
Therefore, the relationship between the gravitational forces when the masses are in air and when they are in water is:
\[ P = Q \]

### Final Answer:
The relation between \( Q \) and \( P \) is:
\[ Q = P \]