Electronics Engineering (ELEX) Board Practice Exam

Which of the following is known as the Universal Flip-flop?

1. D flip-flop

2. T flip-flop

3. J-K flip-flop

4. S-R flip-flop

The correct answer is: J-K flip-flop

The J-K flip-flop is referred to as the Universal Flip-flop because it can be configured to replicate the behavior of the other types of flip-flops, such as the D, T, and S-R flip-flops. This versatility is due to its input structure, which allows for different logic states to be set based on the inputs. In its standard operation, the J-K flip-flop has two inputs, J and K, along with a clock input. The function it performs can simulate the D flip-flop by tying the K input high to create a straightforward data storage mechanism, or it can be used as a T flip-flop by tying the J and K inputs together, effectively toggling the output on each clock pulse when the inputs are active. Moreover, it can behave like an S-R flip-flop by setting specific conditions for the J and K inputs to operate as set and reset signals. The ability to serve as a functional equivalent to these other flip-flop designs makes the J-K flip-flop invaluable in digital design and sequential circuits, solidifying its title as the Universal Flip-flop.