To divide a signal frequency by 4, how many flip-flops are necessary?

To divide a signal frequency by 4, you need to understand how flip-flops function in frequency division. Each flip-flop can divide the frequency of an input signal by a factor of 2.

When a flip-flop receives a digital signal, it toggles its output state every time it receives a clock pulse, effectively halving the frequency of the input signal. Therefore, using a single flip-flop results in a division of the original frequency by 2.

To achieve a division by 4, you need two successive flip-flops. The first flip-flop divides the original frequency by 2, and the second flip-flop then takes this halved frequency as input and divides it by 2 again.

As a result, two flip-flops in series will yield an effective frequency division of 4 (2 * 2 = 4), making the correct answer the requirement of two flip-flops.