A JK flip-flop is a type of which digital element?

• A. Sequential logic circuit
• B. Combinational logic gate
• C. Analog amplifier
• D. Oscillator

Answer: (A)

The main idea here is memory in digital circuits. A JK flip-flop stores a single bit of information and keeps that state between clock transitions, updating only when a clock edge occurs. The next state depends on both the current inputs (J and K) and the previous state, which is the hallmark of sequential logic. Because it uses this internal state and a clock to control when the state changes, it’s not just a pure function of the present inputs, as a combinational gate would be. It also isn’t an analog amplifier or an oscillator, which operate on continuous signals or generate periodic waves without storing state. So the JK flip-flop is a sequential logic circuit.