Electronics

- For : Left side is at , right side at . Since the anode is more negative than cathode, it is reverse biased. - For : Left side is at , right side at . Since the anode is more positive than the cathode, it is forward biased.

Step 1: Analyze the circuit and identify the logic gates.
The given circuit diagram shows three logic gates connected in series. Let's denote the inputs as A and B, and the final output as y.
1. First Gate: This is an AND gate. Its inputs are A and B. Let the output of this gate be .
The Boolean expression for is:
2. Second Gate: This is an OR gate. Its inputs are A and the output of the first gate ( ). Let the output of this gate be .
The Boolean expression for is:
3. Third Gate: This is a NOT gate (inverter). Its input is the output of the second gate ( ). Its output is the final output .
The Boolean expression for is:
Step 2: Simplify the Boolean expression (optional but helpful for verification).
Using Boolean algebra, the expression can be simplified by the Absorption Law, which states that . In our case, and . So, . Therefore, the final output simplifies to:
This means the entire circuit is equivalent to a NOT gate applied to input A.
Step 3: Construct the truth table based on the logical operations.
Let's systematically determine the output for all possible combinations of inputs A and B: Step 4: Compare the derived truth table with the given options.
The derived truth table is:
This matches the truth table provided in Option (2).
The final answer is .

Step 1: Understand the Fundamental Relationship of Currents in a Transistor
In a bipolar junction transistor (BJT), the emitter current ( ) is the sum of the base current ( ) and the collector current ( ). This relationship is based on Kirchhoff's current law applied to the transistor. The fundamental current relationship is given by: Our goal is to find the base current ( ). Rearranging the formula: Step 2: Identify the Given Current Values
Emitter current: Collector current: Step 3: Compute the Base Current
Substitute the given values into the derived formula for : Step 4: Convert the Result to the Required Units (if necessary)
The options are given in A and mA. It's often convenient to convert mA to A for comparison, as . Step 5: Analyze the Options
\begin{itemize} \item Option (1): 50 A. Correct, as it matches our calculated value of . \item Option (2): 0.05 A. Incorrect (this is not ). \item Option (3): 50 mA. Incorrect. \item Option (4): 5 mA. Incorrect. \end{itemize}

In common emitter configuration: Given: , and