Question

please give a written response:

Imagine that your grandmother is in the hospital. She loves to listen to her favorite radio programs, so she asks you to bring the radio from her home to the hospital. The hospital requires you to have a maintenance worker test the radio to make sure it is electrically safe. He finds that it develops 120V on one of its knobs, so he will not let you take it up to your grandmother’s room. She complains that she has had the radio for many years and nobody has ever gotten a shock from it. You end up having to buy a new plastic radio. In your initial post to the discussion, answer the following questions: Is the maintenance worker correct in saying that your grandmother’s radio is not safe to operate in a hospital room? Why or why not? Will the radio be safe back in her bedroom at home? Why or why not?

Answer 1

The hospital maintenance worker is correct. In most of the hospital rooms everything is grounded that is near to any electric socket or machine, including the bed frame. If the grandmother touched the faulty knob while she is also touching the bed frame, she could receive an electric jolt, as there would be a potential difference of 120 V across her. If the 120 V is DC, the shock could send her into ventricular fibrillation. If the 120 V is AC, which is the case in general, the current could produce external and internal burns along the path of conduction. At home, the bed of grandmother is not grounded so there was no path for the circuit to be completed. This is similar to the situation where a bird can sit on a high power cable without getting a shock.