JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV Year INDUSTRIAL ELECTRICAL SYSTEMS Previous Question Paper (February/March - 2022 - R18)

An electric shock occurs when an electric current passes through the human body, typically resulting from contact with a live conductor or faulty equipment. The severity depends on the current magnitude, duration, and path through the body, which can cause muscle contractions, burns, respiratory failure, or cardiac arrest.

If someone has received an electric shock, follow these steps immediately:

1. Ensure your own safety by turning off the power source at the main switch or circuit breaker before touching the victim.
2. If the power cannot be cut, use a non-conductive object like a dry wooden broom or plastic pole to push the victim away from the electrical source.
3. Check the victim's responsiveness and breathing; if they are unconscious and not breathing, initiate CPR immediately.
4. Call emergency services for professional medical assistance.
5. Treat any visible burns by covering them with a sterile, non-stick bandage and keep the victim warm while waiting for help.

In an LT (Low Tension) system, the placement of switches and outlets is governed by safety standards to prevent accidental contact, moisture damage, and fire hazards. Key considerations for their location include:

• Height Requirements: Switches are typically installed at a height of 1.2 to 1.5 meters from the floor level to ensure accessibility while remaining out of reach of small children. Power outlets (sockets) are generally placed 0.3 meters above the floor in living areas, but should be at least 1.0 to 1.2 meters above the floor in kitchens or workbenches to avoid spills and damage.
• Proximity to Water: Switches and outlets must be located at a safe horizontal distance (typically at least 0.6 meters) from water sources like sinks, showers, or bathtubs to prevent short circuits caused by water splashes.
• Accessibility and Convenience: Switches for lighting should be placed near the entrance of a room to allow for immediate illumination. Outlets should be distributed based on the load requirements of appliances, ensuring that heavy-duty appliances like refrigerators or washing machines have dedicated circuits and outlets located near the equipment.
• Environmental Protection: In damp or outdoor locations, switches and outlets must be of an IP-rated (Ingress Protection) weatherproof design with protective covers to prevent the ingress of moisture and dust.
• Clearance: Switches and outlets should not be placed behind doors or in locations where they may be obstructed by furniture, ensuring they remain accessible for maintenance and emergency disconnection.