Newton's gravitational law is not applicable in the case of__________

Options

A. two bodies at different temperatures separated by a distance of 1 km.
B. a body of a smaller mass and another body of a larger mass separated by a large distance.
C. two small masses separated by a large distance.
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Newton's Law of Gravitation**: Newton's law of gravitation states that every point mass attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. The formula is given by:
\[ F = \frac{G \cdot m_1 \cdot m_2}{r^2} \]
where \( F \) is the gravitational force, \( G \) is the gravitational constant, \( m_1 \) and \( m_2 \) are the masses of the two bodies, and \( r \) is the distance between their centers.

2. **Identifying Conditions for Applicability**: The law is applicable under most conditions, including:
- Two bodies of different masses separated by a distance.
- Bodies at different temperatures.
- Bodies of small or large mass.

3. **Finding Exceptions**: The question asks where Newton's law is not applicable. The law does not apply in cases involving:
- Extremely massive bodies where relativistic effects become significant (e.g., black holes).
- Quantum scales where quantum mechanics takes precedence over classical physics.

4. **Conclusion**: Based on the information provided, Newton's gravitational law is not applicable in cases involving extreme conditions such as black holes or at quantum scales. However, in the context of the examples given in the video, it seems that the law is applicable in all the scenarios mentioned.

5. **Final Answer**: Newton's gravitational law is not applicable in the case of extreme gravitational fields (like black holes) or at quantum scales.

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