CET Digital Electronics and Systems

Question 1

What is a logic gate?

Accepted Answer

A circuit that performs a logical operation on inputs.

Answer

A logic gate is a fundamental building block of digital circuits that takes one or more binary inputs (0 or 1) and produces a single binary output based on a specific logical function. Common logic gates include AND, OR, NOT, XOR, NAND, and NOR. These gates are combined to create complex digital systems like microprocessors and memory.

Question 2

What is the purpose of a flip-flop in digital circuits?

Accepted Answer

Answer

A flip-flop is a fundamental sequential logic circuit that can store a single bit of binary information (0 or 1). It has two stable states and can be toggled between them by input signals, typically synchronized by a clock signal. Flip-flops are the basic memory elements used to build registers, counters, and other sequential logic devices crucial for storing and manipulating data in digital systems.

Question 3

What is the role of a microprocessor in digital electronics?

Accepted Answer

Answer

A microprocessor is the central processing unit (CPU) of a computer or embedded system, responsible for executing instructions and performing computations. It fetches instructions from memory, decodes them, performs arithmetic and logical operations, and manages data flow. Essentially, it acts as the 'brain' of a digital system, controlling its overall operation.

Question 4

What does a multiplexer do in digital circuits?

Accepted Answer

Answer

A multiplexer, often called a 'data selector,' is a combinational logic circuit that takes several data inputs and selects one of them to be routed to a single output. The selection of which input to pass through is controlled by a separate set of select lines. This allows multiple data streams to share a single communication channel or for a circuit to choose between different data sources.

Question 5

What is the difference between combinational and sequential circuits?

Accepted Answer

Answer

The key distinction between combinational and sequential circuits lies in their dependence on past inputs. Combinational circuits produce an output that depends solely on the current input values, having no memory of previous states. In contrast, sequential circuits incorporate memory elements (like flip-flops) whose outputs depend not only on current inputs but also on the sequence of past inputs, allowing them to store state information.

(CET) Certified Electronics Technician Practice Test

(CET) Certified Electronics Technician Practice Test

CET Digital Electronics and Systems