OR operation

In AND operation section I have mentioned that there are three basic Boolean operations in digital electronics and OR operation is one of them. In OR operation, if only one input is true then the output will be true. In other words with OR operation we check whether any of the inputs are true (in… Read the rest

AND gate

AND gate is a digital circuit which performs AND operation on inputs. As I discussed in previous section that AND gate gives high output when all inputs are high. In other cases its output must be low (i.e. 0). So we need to design a circuit in that way. Truth table for AND gate Figure… Read the rest

AND operation

AND gate symbol There are three basic operations in digital electronics, i.e. OR, AND and NOT operation. At first I would like to discuss about AND operation. When all the input conditions are true then the output will be true. If one or more input conditions are false, output will be false. In simple words… Read the rest

Sea salt and Table salt

For thousands of years salt was a very important commodity. Producing salt from sea water wasn’t easy but salt was necessary for preserving foods. In fact salt enabled human civilization to preserve foods. It was a very expensive commodity and in sometimes roman armies were paid in salt. The word salary comes from the Latin… Read the rest

How ATM works

Automated teller machine or ATM also known as cash machine gives you money whenever you need. You just insert a plastic card, enter a pin number and the machine delivers the exact amount you asked for. But what goes inside the machine? Cash machine connects to a central data processor where your account details are… Read the rest

First moon landing

Watch the video of first moon landing on July 20, 1969. It was NASA’s Apollo 11 mission which started the beginning of a new era, in Neil Armstrong’s words it was “one small step for man, one giant step for mankind”.… Read the rest

Make a basic electric motor

Electric motor converts electrical energy into mechanical energy. To understand the working principle you can build a simple motor at home. For this experiment you will need thin insulated wire, battery, paper clip or safety pin, tape, scissors, crocodile clip and adhesive tape. First video is very simple; it shows how to build simple motor… Read the rest

Why do we put salt on icy road instead of heating?

Instead of heating we use salt to melt snow. Because snow will continue to fall on road and freeze again, but salt decrease freezing point and prevents forming of ice. Usually table salt sodium chloride is used but calcium chloride is twice effective than sodium chloride and used in countries like Russia. Do you know… Read the rest

Washing hair in space

Every astronauts floats like superheroes in the weightless environment of space station. Not only astronauts everything including water floats there, so without running water washing hair isn’t easy. In this video astronaut Karen Nyberg shows how she washes her hair with shampoo in space. It’s different and tricky.… Read the rest

Lemon battery

Making a lemon battery is very easy. Lemon contains citric acid and with the help of citric acid two different metals can generate electricity. You will need lemon, copper coin, zinc coated nail, crocodile clip, multimeter and a LED to make battery. It can be a science fair project also. So watch this hilaroad video… Read the rest