Question

In a transistor, the current gain is defined as:

• A. \( \beta = \frac{I_C}{I_B} \)
• B. \( \beta = \frac{I_E}{I_B} \)
• C. \( \beta = \frac{I_C}{I_E} \)
• D. \( \beta = \frac{I_B}{I_E} \)

Hint:

The current gain \( \beta \) in a transistor is always defined as \( \beta = \frac{I_C}{I_B} \), where \( I_C \) is the collector current and \( I_B \) is the base current.

Answer 1

The Correct Option is A

In the context of transistors, the current gain, commonly denoted by \( \beta \), is an important parameter. It is defined primarily for Bipolar Junction Transistors (BJTs) and represents the ratio of the collector current (\( I_C \)) to the base current (\( I_B \)). This parameter is crucial because it reflects how much the base current is amplified to produce the collector current.

The formula for the current gain is given by:

\[\beta = \frac{I_C}{I_B}\]

Here, \( I_C \) is the collector current, and \( I_B \) is the base current. This equation shows that \( \beta \) is a measure of the amplification capabilities of the transistor. It is a dimensionless number and typically has values ranging from about 20 to over 1000, depending on the type of transistor.

Thus, the correct answer from the options provided is:

\( \beta = \frac{I_C}{I_B} \)