For a full wave rectifier, if the input frequency is 50Hz,the output frequency will be _______.

The correct option/answer is 100Hz.

To understand why the output frequency of a full-wave rectifier is twice the input frequency, let us look at the rectification process step-by-step.

A full-wave rectifier converts both half-cycles of an alternating current (AC) input signal into a pulsating direct current (DC) output signal.

During the positive half-cycle of the input AC signal, the rectifying diodes conduct in such a way that the current flows through the load in a specific direction, producing a positive output pulse.

During the negative half-cycle of the input AC signal, the diodes switch their states, but they still direct the current through the load in the same direction as before. This produces another positive output pulse for the negative half of the input cycle.

Therefore, for one complete cycle of the input wave (which consists of one positive and one negative half-cycle), we obtain two output pulses in the same direction.

Since frequency is defined as the number of cycles completed per second:
If the input AC signal has a frequency of $f_{\text{in}}$ , then the output ripple frequency $f_{\text{out}}$ will be:
$$f_{\text{out}}=2\times f_{\text{in}}$$
Given that the input frequency is 50Hz:
$$f_{\text{out}}=2\times 50\text{Hz}=100\text{Hz}$$
Hence, the output frequency of the full-wave rectifier is 100Hz.