Which of the following circuit is used to store one bit of data ?

Answer: Flip-Flop

Explanation: A flip-flop is a bistable storage element that can hold one bit of information (either 0 or 1).

How it stores one bit:

• It has two stable states representing the logical 0 and 1.

• Clocked flip-flops (for example, D flip-flops) capture the input on a clock edge and hold that value until the next update.

• Common flip-flop types include SR, D, JK, and T, each implementing bit storage with different control behaviors.

Why the other circuits are not correct:

• An encoder converts multiple inputs into a binary code; it performs code conversion, not data storage.

• A decoder converts a binary code into a specific output line; it decodes signals rather than storing them.

• A register is a collection of flip-flops used to store multiple bits (for example, an 8-bit register holds eight bits). A register therefore stores more than one bit, whereas a single flip-flop stores exactly one bit.

Conclusion: Because a flip-flop is the basic bistable element that holds a single binary value, it is the correct circuit to store one bit of data.