Question 44

The Correct Answer is B **Explanation for Option B (analog to digital converter):** An Analog-to-Digital Converter (ADC) is an electronic circuit designed to take a continuous, variable analog signal (such as voltage, temperature, or pressure) and convert it into a discrete digital signal (represented by binary numbers). Looking at Figure "A" (assuming the standard illustration for this context, typically showing a trapezoidal block with an analog input on one side and a digital output on the other), the key indicators that the unit is an ADC are: 1. **Input Type:** The circuit takes in an **analog** signal (often depicted as a continuously varying wave or a single line labeled "Analog Input"). 2. **Output Type:** The circuit produces a **digital** signal (often depicted as parallel lines representing the binary bits, labeled "Digital Output"). 3. **Function:** The core purpose of the unit is the transformation from analog format to digital format. **Explanation for Incorrect Options:** **A) digital to analog converter (DAC):** A DAC performs the opposite function of an ADC. It takes a digital input (binary code) and converts it back into a continuous analog output signal. If the flow in Figure A were reversed (digital in, analog out), this would be the correct answer. **C) multiplexer:** A multiplexer (MUX) is a data selector that takes several digital input signals and routes only one of them onto a single output line based on a control signal. It deals exclusively with digital signals and does not perform the analog-to-digital transformation. **D) de-multiplexer:** A de-multiplexer (DEMUX) performs the reverse function of a MUX. It takes a single digital input signal and routes it to one of several output lines, again controlled by a select signal. Like the MUX, it only operates on digital signals.