Assertion: Suceptibility is defined as the ration of intensity of magnetisation I to magnetic intensituy H.
Reason: Greater the value of susceptibility smaller the value of intensity of magnetisation I.

Options

A. If both Assertain and Reason are true and Reason is the correct explanation of Assertain
B. If both Assertain and Reason are true but Reason is not correct explantion of Assertain
C. If Assertion is true but Reason is false
D. If Assertion is false but Reason in true.

Explanation

To analyze the given statements regarding magnetic susceptibility, we will break down the assertion and reason step by step.

### Step 1: Understanding the Assertion
The assertion states that "Susceptibility is defined as the ratio of intensity of magnetization (I) to magnetic intensity (H)."

- **Magnetic Susceptibility (χ)** is indeed defined as:
\[ \chi = \frac{I}{H} \]
where:
- \(I\) is the intensity of magnetization.
- \(H\) is the magnetic field intensity.

### Step 2: Evaluating the Assertion
Since the definition given in the assertion is correct, we conclude:
- **Assertion is True.**

### Step 3: Understanding the Reason
The reason states that "Greater the value of susceptibility, smaller the value of intensity of magnetization (I)."

- This statement implies an inverse relationship between susceptibility and intensity of magnetization, which is incorrect.
- In fact, a greater susceptibility indicates that a material can be magnetized more easily, which means that for a given magnetic field intensity \(H\), the intensity of magnetization \(I\) would be greater.

### Step 4: Evaluating the Reason
Since the reason contradicts the relationship defined by susceptibility, we conclude:
- **Reason is False.**

### Conclusion
- The assertion is true, and the reason is false. Therefore, the correct option is that the assertion is true, and the reason is false.

### Final Answer
- **Assertion: True**
- **Reason: False**