Both AC (Alternating Current) and DC (Direct Current) can be dangerous, but AC is generally considered more dangerous to humans than DC for several reasons:

1. Effect on the Heart:

AC can cause

ventricular fibrillation a dangerous and irregular heartbeat, even at lower currents (as low as 100-300 mA at 60 Hz). This is because AC repeatedly passes through zero, making it more likely to interfere with the natural rhythm of the heart.

DC tends to cause muscle contractions, and while it can still be dangerous, it often causes the victim to be "thrown" away from the current source due to the strong muscle contraction, whereas AC may cause muscles to "freeze" and prolong the exposure.

2. Frequency Factor:

- The standard household AC frequency (50-60 Hz) is particularly dangerous because it's close to the natural frequency of the human heart, increasing the likelihood of fibrillation.

3. Perception and Let-Go Threshold:

- AC has a lower

let-go threshold meaning that at certain currents, a person may not be able to let go of the conductor due to involuntary muscle contractions. With DC, while still dangerous, the let-go threshold is higher.

4. Peak Voltage:

- For the same root-mean-square (RMS) voltage, AC reaches a peak voltage that is about 1.414 times higher than DC. For instance, 230V AC has a peak voltage of about 325V, which can cause more severe electric shock compared to 230V DC.

However (DC) can also be highly dangerous, especially at high voltages (e.g., electric cars, batteries in certain applications). Both AC and DC require careful handling and appropriate safety measures.