A 50 Hz AC source, a diode, and a resistor are wired together in...

The given circuit consists of an AC source, a diode, and a resistor connected in series, which forms a half-wave rectifier.

In a half-wave rectifier, the diode is forward-biased and conducts current only during one half of the AC cycle.

Thus, for every complete cycle of the AC input, exactly one current pulse flows through the resistor.

The frequency of the AC source is given as $50 \text{ Hz}$, which means there are $50$ complete cycles per second.

Therefore, the number of current pulses per second flowing through the resistor is $50$.