Cognizant Interview Questions and Answers

Setup time and hold time are timing constraints in digital circuits to ensure proper operation of flip-flops.

• Setup time is the minimum amount of time data must be stable before the clock edge for it to be reliably sampled.

• Hold time is the minimum amount of time data must be stable after the clock edge for it to be reliably sampled.

• Setup time violations can lead to metastability issues in flip-flops.

• Hold time violations can lead to data corruption in flip-flops.

• Setup time is i...read more

A mux (multiplexer) is a digital circuit that selects one of multiple input signals and forwards it to a single output.

• Mux is used to select one of multiple input signals based on the select lines.

• The number of select lines determines the number of input signals that can be selected.

• Common examples of mux include 2:1 mux, 4:1 mux, and 8:1 mux.

Universal gates are gates which can be used to implement any other gate. NAND and NOR gates are examples of universal gates.

• Universal gates can be used to implement any other gate in digital circuits.

• NAND gate and NOR gate are examples of universal gates.

• NAND gate can be constructed using NOR gates by applying De Morgan's theorem.

Sequential circuit is a type of digital circuit where the output depends not only on the present input but also on the history of the input.

• Sequential circuit stores information about past inputs, unlike combinational circuits.

• Flip flop is a basic building block of sequential circuits, used to store one bit of information.

• Flip flops have two stable states (0 or 1) and are used for storing binary information.

• Examples of flip flops include D flip flop, JK flip flop, and T flip ...read more

MOSFET stands for Metal-Oxide-Semiconductor Field-Effect Transistor, a type of transistor used in electronic devices.

• MOSFET is a type of field-effect transistor that is commonly used in integrated circuits.

• It consists of a metal gate electrode separated from the semiconductor by a thin insulating layer of oxide.

• MOSFETs are used for amplifying or switching electronic signals in devices like computers, smartphones, and power amplifiers.