National Bird Day is celebrated every year on 5 January . This day is observed to spread awareness about birds, their importance in nature, and the need to protect them. Birds are beautiful living beings and play a very important role in keeping our environment healthy. Origin of National Bird Day National Bird Day was first celebrated in the year 2002 . It was started by bird lovers and environmental groups to protect birds from dangers like deforestation, pollution, and illegal hunting. The main aim of this day is to teach people, especially students, why birds are important and how we can help save them. Why Is National Bird Day Celebrated Every Year? National Bird Day is celebrated every year because many bird species are disappearing due to human activities. Cutting trees, using plastic, pollution, and climate change are harming birds and their homes. This day reminds us that: Birds need protection Nature should be respected Everyone has a responsibil...
Breakdown and resistance of diode Breakdown of a diode On applying reverse bias to the diode, two types of breakdown occurs, which are responsible to the sudden increase of current in the reverse bias condition. Avalanche breakdown In this mechanism, the minority charge carriers gain enough kinetic energy from the applied reverse voltage to collide with the valence electrons of the atom and liberate them. In this process the covalent bond breaks and create a large number of electron-hole pairs. The new charge carriers so produced generate the additional electron-hole pairs. In this way the number of free electrons and holes increases continuously. This phenomenon is known as avalanche multiplication and it produces a sharp increase in the reverse current. The magnitude of avalanche breakdown voltage can be increased by increasing the temperature. Zener breakdown If the junctions are heavily doped and have a very narrow...