Basic electrical theory and the dangers of electricity

Ohm's law: current = voltage ÷ resistance, so 230 ÷ 46 = 5 A. Option d comes from multiplying instead of dividing.

Source: Ohm's law (basic electrical science) (I = V / R)

Touching the casualty while they are in contact with the supply can make you a second casualty, so break the circuit first by switching off and isolating, then call 999 and give first aid such as CPR if needed. Pulling them by the arm is the most tempting choice but puts you in the current path. HSE guidance on electrical safety and first aid.

Source: HSE guidance on electrical safety and first aid (Electric shock: break contact with the supply before touching the casualty)

Warning signs are triangular, with a yellow background, black border and black symbol, such as the lightning flash for electrical danger. Blue circles are mandatory signs (you must do something), red circles with a bar are prohibition signs and green rectangles show safe conditions. Health and Safety (Safety Signs and Signals) Regulations 1996.

Source: Health and Safety (Safety Signs and Signals) Regulations 1996 (Schedule 1, warning signs)

Current passing through the body can burn muscles, nerves and blood vessels along its path, so the damage inside can be far worse than the small entry or exit marks on the skin. Anyone who has had a significant electric shock should be checked by a medical professional. HSE guidance on electrical injuries.

Source: HSE Electrical injuries (Burns along the length of the current flow)

Even a shock too small to harm you directly can make you jerk away and fall. Falls from height are a major cause of serious injury and death, so a minor shock on a ladder or scaffold can be very dangerous. This is one more reason to isolate before work. HSE guidance on electrical injuries.

Source: HSE Electrical injuries (Loss of muscle control: falls when working at height)