During clocking, which device toggles its state, causing inputs and outputs to switch between 1 and 0?

During clocking, which device toggles its state, causing inputs and outputs to switch between 1 and 0?

• A. D Flip-flop
• B. J-K Flip-flop
• C. T Flip-flop
• D. SR Latch

Answer: (B)

The key idea is how edge-triggered flip-flops respond to their inputs on a clock edge. A J-K flip-flop has a special toggle condition: when both J and K are logic 1, the next state is the complement of the current state. In other words, on each clock edge the output flips from 0 to 1 or from 1 to 0. That toggling behavior directly matches the description of inputs and outputs switching between 1 and 0 as the clock occurs. To connect the other options: a D flip-flop simply captures the D input at the clock edge and presents that value at the output—it doesn’t inherently toggle. An SR latch is typically not clocked and can enter an invalid state if both S and R are asserted. A T flip-flop does toggle when its T input is high, but that’s a specific toggle input condition; the J-K flip-flop is the classic device that toggles on a clock edge specifically when both inputs are high, making it the best fit for the described situation.

The key idea is how edge-triggered flip-flops respond to their inputs on a clock edge. A J-K flip-flop has a special toggle condition: when both J and K are logic 1, the next state is the complement of the current state. In other words, on each clock edge the output flips from 0 to 1 or from 1 to 0. That toggling behavior directly matches the description of inputs and outputs switching between 1 and 0 as the clock occurs.

To connect the other options: a D flip-flop simply captures the D input at the clock edge and presents that value at the output—it doesn’t inherently toggle. An SR latch is typically not clocked and can enter an invalid state if both S and R are asserted. A T flip-flop does toggle when its T input is high, but that’s a specific toggle input condition; the J-K flip-flop is the classic device that toggles on a clock edge specifically when both inputs are high, making it the best fit for the described situation.