BCA Semester 1 – Digital Logic – Unit 4: Counters & Registers

Question 1

What are the drawbacks of clocked RS Flip Flop? Explain the operation of JK Flipflop along with its circuit diagram and characteristic table.

Marks: 5

Year: 2019 Final TU FOHSS

Drawbacks of Clocked RS Flip‑Flop - The basic (clocked) RS Flip‑Flop (or gated RS) has a fundamental problem when both inputs S (Set) and R (Reset) are 1 — this creates an invalid / undefined state

Question 2

What is T-Flip Flop? Explain clocked JK Flip-Flop with its logic diagram and truth table.

Marks: 5

Year: 2019 Final TU FOHSS

1. T-Flip Flop Definition: A T (Toggle) Flip-Flop is a type of flip-flop that changes its output state (toggles) when the input T = 1 on the clock pulse. If T = 0, the output remains unchanged. Key

Question 3

Explain JK and T Flip Flop with their Logic and Diagram, graphical symbol, characteristic table, characteristic equation and excitation table.

Marks: 10

Year: 2020 Final TU FOHSS

1. JK Flip-Flop a) Definition - JK Flip-Flop is a bistable device with two inputs, J and K, a clock input, and outputs Q and Q'. - It can act as SR Flip-Flop but without invalid states (no race con

Question 4

Explain clocked JK flip flop with logic diagram, truth table, characteristic table and excitation table.

Marks: 5

Year: 2021 Final TU FOHSS

1. Definition - A JK Flip-Flop is a bistable multivibrator with two inputs (J and K), a clock input (CLK), and outputs Q and Q'. - It is edge-triggered (changes state on clock edge). - Function:

Question 5

What is race around condition? Explain how JK master flip flop is used to eliminate race around condition.

Marks: 5

Year: 2022 Final TU FOHSS

1. What is Race Around Condition? Race-around condition occurs in a JK flip-flop when: - J = 1 and K = 1 - Clock pulse is HIGH for a duration longer than the propagation delay During this time, th

Question 6

What is register? Explain types of registers depending on input output with its block diagram & logic diagram.

Marks: 10

Year: 2022 Final TU FOHSS

1. Definition - A register is a group of flip-flops used to store binary data. - Each flip-flop stores 1 bit, so a register of n flip-flops can store n-bit data. - Registers can be used for data stora

Question 7

What is a synchronous sequential circuit? Explain RS NAND latch with block diagram, logic diagram, truth table, and timing diagram.

Marks: 5

Year: 2023 Final TU FOHSS

1. Definition: Synchronous Sequential Circuit A synchronous sequential circuit is a digital circuit in which the outputs change only at specific instants of time controlled by a clock signal. Key Fe

Question 8

Define register. Explain serial-in serial-out register with working mechanism for data input 11010

Marks: 5

Year: 2023 Final TU FOHSS

1. Definition: Register A register is a sequential digital circuit composed of flip-flops that can store multiple bits of data. Key Features: - Can store n-bit binary data. - Used for temporary da

Question 9

How does a flip-flop differ from a latch? Explain clocked SR flip-flop with logic diagram, truth table, characteristic table, and excitation table.

Marks: 5

Year: 2024 Final TU FOHSS

1. Difference between Flip-Flop and Latch | Feature | Latch | Flip-Flop | |-----------------------|-------------------------------|-------

Question 10

Explain how race condition in JK flip-flop can be resolved. A sequential circuit with two D Flip-Flops (A, B), inputs x,y, and output z is defined by: \[ A(t+1)=xy′+xB \] \[ B(t+1)=x′B+xA \] \[ z=A \]

Marks: 10

Year: 2024 Final TU FOHSS

1. Race Condition in JK Flip-Flop Definition: - A race condition occurs in a JK flip-flop when both J=K=1 and the clock pulse is high for too long, causing the output to toggle multiple times uninte