Assertion (A) : The resistivity of conductor increases with the increasing of temperature.
Reason (R): The resistivity is the reciprocal of the conductivity.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false.
D. A is false and R is true.

Explanation

To solve the question, we need to analyze the Assertion (A) and the Reason (R) provided.

**Step 1: Analyze the Assertion (A)**
The assertion states that "The resistivity of a conductor increases with the increasing of temperature."
- This statement is true. As the temperature of a conductor increases, the atoms in the conductor vibrate more, which increases the chances of collisions between the charge carriers (electrons) and the atoms. This leads to an increase in resistivity.

**Step 2: Analyze the Reason (R)**
The reason states that "The resistivity is the reciprocal of the conductivity."
- This statement is also true. Resistivity (ρ) and conductivity (σ) are related by the equation:
\[ \rho = \frac{1}{\sigma} \]
However, while this statement is correct, it does not explain why resistivity increases with temperature.

**Step 3: Conclusion**
Both the assertion and the reason are true, but the reason does not provide a correct explanation for the assertion. Therefore, the correct answer is that both statements are true, but the reason is not the correct explanation of the assertion.

**Final Answer:**
Assertion (A) is true. Reason (R) is true, but it is not the correct explanation of Assertion (A).

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