Electrical Engineering Insights: Decoding Railway Track Wiring

 

Rajeev: Hey Divya, can I ask you a question about electrical appliances?

Divya: Sure, go ahead Rajeev.

Rajeev: How many wires are there in all your electrical appliances?

Divya: There are usually two wires.

Rajeev: That's right. Any electrical instrument works only if the path of electricity is completed.

Divya: Hmm, I see. So, Rajeev, let me ask you a question. We have traveled by train many times. Have you noticed how many wires are visible overhead on the railway track?

Rajeev: Only one wire is visible on the railway track overhead.

Divya: Yes, exactly! But why is that?

Rajeev: Well, the rail runs on electricity, so you would expect it to be connected to two wires for completing the path. However, if there were two wires, it would need two spring systems to connect, which would increase the mechanical complexity and the cost of making electrical poles and wires. In fact, the railway track itself acts as the second wire, connecting to the ground.

Divya: Oh, I see. But then why don't we get shocked when we touch the railway track?

Rajeev: That's because the railway track is laying on the ground, and we are also standing on the ground. Both are at the same potential, so we do not get shocked.

Divya: Ah, I understand now. Thanks for explaining, Raj. I never knew there was so much complexity involved in the wiring of railway tracks.

Rajeev: You're welcome, Diya. It's always interesting to learn about the science and engineering behind everyday things we use. Do you have any other questions about electrical appliances or any other topic?

Divya: Not at the moment, but I'll definitely let you know if I do. Thanks again for your explanations, Rajeev.

Rajeev: No problem, Divya. I'm always here to help. Just let me know if you need anything.