In the following question a statement of assertion (A) is followed by a statement of reason (R )
A : work done by the field of a nucleus in a complete orbit of the electron is zero even if the orbit is elliptical .
R : Electrostatic force is conservative in nature.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1).
B. If both Assertion & Reason are true but the reason is not correct explanation of the assertion then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements , then mark (4).

Answer

To analyze the given assertion (A) and reason (R), we can break down the problem step by step.

### Step 1: Understanding the Assertion
The assertion states that the work done by the field of a nucleus on an electron in a complete orbit is zero, even if the orbit is elliptical.

### Step 2: Understanding the Reason
The reason provided states that the electrostatic force is conservative in nature. A conservative force is one where the work done by the force on an object moving between two points is independent of the path taken.

### Step 3: Analyzing the Nature of Electrostatic Force
Electrostatic forces, such as those between charged particles, are indeed conservative forces. This means that when a charged particle moves in an electrostatic field, the work done by the field over a closed path (like a complete orbit) is zero.

### Step 4: Applying the Concept to the Assertion
Since the electrostatic force is conservative, the work done by the electrostatic field on the electron as it moves in a closed path (like an elliptical orbit) will be zero. This applies regardless of the shape of the orbit (circular or elliptical).

### Step 5: Conclusion
Both the assertion (A) and the reason (R) are correct. Furthermore, the reason provided explains the assertion accurately. Therefore, the correct conclusion is that both statements are true and the reason supports the assertion.

### Final Answer
Both the assertion and reason are correct, and the reason explains the assertion.