Question 4. An overhead power line for an electric train is suspended at short intervals by...
Question 4. An overhead power line for an electric train is suspended at short intervals by thin wires 1m long from the ceiling of a tunnel. If the powerline is duplicated by another one parallel to the first at a separation of 100mm, find the maximum current that can be carried in each cable at the same time before the cables touch. The cables weigh 2kg per metre of length and have a diameter of 20mm.