Question 49Electricity & Electronics - QMED

The correct answer is B) 60 Hz AC systems. The reason is that 60 Hz AC systems are the most dangerous for human contact compared to DC systems or higher frequency AC systems. This is because the human body's natural electrical conduction responds most strongly to 60 Hz AC, which can cause severe muscle contractions, cardiac arrest, and other life-threatening effects. In contrast, DC systems and higher frequency AC systems are generally less likely to produce the same level of physiological impact during electrical contact. The other options are incorrect because DC systems are generally less dangerous than 60 Hz AC, and higher frequency AC systems like 10 kHz are also less hazardous compared to the 60 Hz frequency that the human body is most sensitive to.