Category Archives: Technology

NOT operation

NOT operation is the last basic Boolean operation. We have seen in OR and AND operation that these are performed on two or more inputs. But NOT operation is performed on single input. NOT operation simply gives opposite logic state of its input logic state. i.e. if input logic is 1 output will be 0… Read the rest

OR gate

OR gate is a digital circuit which performs OR operation on inputs. In OR operation section I discussed about the Boolean logic, OR operation. If any input is true the output is true. So OR gate is a digital circuit where output goes to high state (1) if any of the inputs are high. The… Read the rest

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

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

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

Are MRIs safe?

Ionizing radiation like X-ray can be harmful. But to date no study has claimed that MRI is harmful. Instead of radiation a giant magnet is used to take image of body parts inside which may be your brain, heart or anything. One danger of MRI is its strong magnet attracts metal. So technicians ensure no… Read the rest

Death-proof safety elevator

Today’s safety elevators don’t fall when cable breaks. A lock invented by American industrialist Elisha Otis locks the elevator while descending at high speed and hence prevents falling. This death defying elevator was introduced in 1852. Watch this discovery channel video to see how it was invented.… Read the rest