Electronics Engineering (ELEX) Board Practice Exam

What is the overall transfer function from block diagram reduction for cascaded blocks?

1. Product of individual gain

2. Sum of individual gain

3. Maximum individual gain

4. Average individual gain

The correct answer is: Product of individual gain

The overall transfer function for cascaded blocks is derived by multiplying the transfer functions of each individual block. In a cascaded system, the output of one block serves as the input to the next. This means that the output signal is influenced by each block's gain sequentially. When you multiply the transfer functions of these blocks, you effectively combine their effects on the signal being processed. This is fundamental in control systems and signal processing, which rely on the principles of linear time-invariant (LTI) systems, where the output is directly proportional to the input. The product of individual gains allows for the analysis of how the system as a whole behaves. This multiplication reflects the system's cumulative effect on the input signal, capturing the way signals are transformed as they pass through each component of the cascade. In contrast, other options like the sum, maximum, or average of individual gains do not represent the correct operation for cascaded systems since these do not accurately reflect how the flow of signals through multiple stages affects the resulting output.