Assertion : When baseregion has larger width, the collector current increases.
Reason : : Electron hole combination in base result in increase of base current.

Options

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

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states: "When the base region has larger width, the collector current increases."

- In a transistor, particularly in an NPN transistor, the base region is sandwiched between the emitter and collector. The width of the base region can affect the behavior of the transistor.
- A wider base region means that there is a greater chance for electron-hole recombination to occur within the base. This can lead to an increase in the base current.

### Step 2: Analyze the Collector Current
The collector current (Ic) in a transistor is related to the emitter current (Ie) and the base current (Ib) by the equation:
\[ I_e = I_b + I_c \]

- If the base current increases due to a wider base region, it implies that the emitter current is also affected. However, the collector current is primarily determined by the amount of charge carriers that can cross from the emitter to the collector.
- With a larger base width, although the base current increases, it can lead to more recombination of carriers, which can ultimately reduce the number of carriers that reach the collector.

### Step 3: Understand the Reason
The reason states: "Electron-hole combination in base results in increase of base current."

- This statement is true. A wider base allows for more electron-hole recombination, which indeed increases the base current.

### Step 4: Conclusion
- The assertion is **false** because a larger base width does not lead to an increase in collector current; it can actually decrease it due to increased recombination.
- The reason is **true** as it correctly describes the effect of a wider base on base current.

### Final Answer
- The assertion is false, and the reason is true. Thus, the correct option is that the assertion is false, and the reason is true.