Assertion: First law of thermodynamics can be applied for ideal gases only.
Reason: First law is simply, law of consevation of energy.

Options

A. (a) If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. (c) If Assertion is true, but the Reason is false.
D. (d) If Assertion is false but the Reason is true.

Explanation

To solve the question regarding the assertion and reason related to the First Law of Thermodynamics, we will analyze both statements step by step.

### Step 1: Understand the Assertion
The assertion states: "First law of thermodynamics can be applied for ideal gases only."
- The First Law of Thermodynamics is a principle that applies to all thermodynamic systems, not just ideal gases. It states that energy cannot be created or destroyed, only transformed from one form to another. Therefore, this assertion is **false**.

### Step 2: Understand the Reason
The reason states: "First law is simply the law of conservation of energy."
- This statement is true. The First Law of Thermodynamics is indeed a manifestation of the law of conservation of energy, which asserts that the total energy in an isolated system remains constant.

### Step 3: Conclusion
Based on the analysis:
- The assertion is **false** because the First Law applies to all systems, not just ideal gases.
- The reason is **true** as it correctly describes the First Law as a conservation law.

### Final Answer
Thus, the correct conclusion is that the assertion is false, and the reason is true. Therefore, if we are given options, we would select the one that states "Assertion is false, but Reason is true."

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