What is Iris scanning? How it is different from fingerprint scanning?

We, human beings, have 3 things which are unique in each and every individual. They are fingerprints, DNA and iris pattern. Most of you must know about fingerprints and DNA scanning as they are widely used now-a-days. But do you ever thought how iris in our eyes helps to get us authenticated?

What is Inverter AC? How it is different from normal AC?

Summer is in dominant mood and everyone is looking forward to get relief from it. Most of us are using air conditioners (AC) for the same. I hope you must aware of a normal AC which is available in most of the electronics shop. But, Do you know, there is another type of AC known as Inverter AC?

Is the working of diesel and electric locomotive same?

Locomotive engines are the most important thing in railways. Normally there are 3 types of locomotives. They are steam, diesel and electric locomotive engines. Diesel and electric engines are mostly used by railways. Without diesel or electric power, engines don’t work. But do you know, the working principle of both the locomotive engines is same?

Why Air Conditioner (AC) capacity is measured in tons?

Most of us are using Air Conditioner to fight with summer heat. It makes everyone to feel relaxed in summer. Do you ever observe the specification of air conditioner. You will find that its cooling capacity is measured in ton and not in KW or something else. Why it is in tons?

Why do sand is sprayed on railway track by engine?

Almost everyone must travelled in train. It is the most common means of transport. Trains are used for moving both passengers and goods from one place to another. We all know that train is run by a rail engine. Do you know, apart from energy sources, the most important thing to run a train is sand?