Assertion : Two p-n junction diodes placed back to back, will work as a n-p-n transistor.
Reason: The p-region of two p-n junction diodes back to back will form the base of n-p-n transistor.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true not but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Explanation

To analyze the given assertion and reason, let's break down the concepts step by step.

### Step 1: Understanding the Assertion
The assertion states that two p-n junction diodes placed back to back will work as an n-p-n transistor.

**Explanation**:
A transistor, specifically an n-p-n transistor, consists of two n-type semiconductor materials separated by a thin layer of p-type material. In contrast, a p-n junction diode consists of a single p-n junction. When two p-n junctions are placed back to back, they do not create the necessary structure or doping concentrations required for an n-p-n transistor.

### Step 2: Understanding the Reason
The reason given is that the p-region of the two p-n junction diodes back to back will form the base of the n-p-n transistor.

**Explanation**:
In an n-p-n transistor, the base (which is the p-type material) must have a lower concentration of holes (p-type carriers) compared to the n-type materials (which have a higher concentration of electrons). When two p-n junctions are placed back to back, the p-regions do not fulfill the necessary conditions for the base of an n-p-n transistor, as they do not have the appropriate doping concentrations.

### Step 3: Conclusion
Since both the assertion and the reason are incorrect, we conclude that the statement is false.

**Final Answer**: Both the assertion and the reason are false.