Logic Circuits III - SS2 ICT Past Questions and Answers - page 2

An AND gate is a logic gate that outputs 1 only when both of its inputs are 1. The truth table shows that when both inputs A and B are 1, the output is 1. In all other cases, when at least one of the inputs is 0, the output is 0.

A NOT gate, also known as an inverter, produces an output that is the opposite of its input. When the input is 0, the output is 1, and vice versa. The significance of a NOT gate lies in its ability to change the logical state of a signal. It's commonly used to complement signals, invert logic levels, and control the flow of data in digital circuits.

An OR gate produces an output of 1 if at least one of its inputs is 1. If both inputs are 0, the output is 0. An example scenario is a home security system with multiple sensors (doors, windows, motion detectors). The system's alarm is triggered (output is 1) if any of the sensors detect an intrusion (input is 1), representing a real-world use of an OR gate.

Both AND and OR gates take two inputs and produce a single output, but their behavior differs. An AND gate produces 1 only when both inputs are 1, whereas an OR gate produces 1 if at least one input is 1. In terms of output values, AND gates tend to produce more 0s, as they require both inputs to be 1 for a 1 output. OR gates produce more 1s, as they need just one input to be 1 for a 1 output.

Complex digital circuits require a variety of logical operations to process and manipulate data. By combining different logic gates like AND, OR, and NOT gates, engineers can create intricate circuit designs that perform complex tasks. These designs allow for arithmetic operations, decision-making, memory storage, and control of various electronic devices, contributing to the functionality of computers, smartphones, and other digital systems.