Exam Question

### (a) Hazards while Working on Electrical Machinery (4 Marks)
Working on or near electrical machinery, particularly in a shipboard environment, presents several severe hazards. The primary risks are:
1. **Electric Shock:** This is the physiological reaction or injury caused by electric current passing through the body. On ships, the risk is significantly elevated compared to shore-based installations due to factors like high humidity, wetness from leaks or condensation, and high ambient temperatures. These conditions reduce the electrical resistance of the human body, meaning that even voltages considered low (e.g., less than 60V) can become fatal. Contact with live conductors can cause muscle contractions, fibrillation of the heart, and death.
2. **Electrical Burns:** When a high current passes through the body, the heat generated (Joule heating, $$P = I^2 R$$) can cause deep and severe tissue burns along the current's path. These are often more severe internally than they appear on the skin. Burns can also occur from direct contact with overheated electrical components.