Solar Cooker:-    " The solar Cooker is a device which is used to cook food by utilising the energy radiated by the sun". A solar Cooker consists of an insulated metal box or wooden box which is painted all black from inside. There is a thick glass sheet cover over the box and a…

Moving air is called wind. Wind has a energy. The energy possessed by wind is due it's high speed (or motion). So, the wind kinetic energy. It this kinetic energy of wind which is utilised for doing work. Solar energy (or sun's energy) is responsible for the blowing of wind. Wind …

Flowing water possesses kinetic energy. The energy of flowing water has been traditionally used for rotating the water wheels and drive- water mills to grind wheat to make flour. The traditional use of energy of flowing water has been modified by improvements in technology and use to ge…

" The Sun and the surrounding sky appear red at sunrise and at sunset because at that time most of the blue colour present in sunlight has been scattered out and away from our line of sight, leaving behind mainly red colour in the direct sunlight beam that reaches our eyes".  …

" The scattering of blue component of the white sunlight by air molecules present in the atmosphere causes the blue color of the sky". This can be explained as follows. The sunlight is made up of seven coloured lights mixed together. When sunlight passed  through the atmospher…

Scattering of light means to throw light in various random directions. Light is scattered when it falls on various types of suspended particles in its path. Depending on the size of particles, she the scattering can be of white sunlight as such or of the coloured lights which make up th…

We know that when light goes from one medium to another medium having different optical densities,then refraction of light rays (or bending of light rays) takes place. Now, in the atmosphere, we have air everywhere. But all the air in the atmosphere is not at the same temperature 🌡️. S…

The main constituent of petroleum gas is butane that it also contains smaller amounts of propane and erhane. Thus, we can say that petroleum gas ⛽ is a mixture of three hydrocarbons: butane, propane and ethane. Butane, propane and ethane, all burn readily producing a lot of heat. This m…

When an electric current is passed through a high resistance wire, like nichrome wire, the resistance wire becames very hot and produces heat. This is called the heating effect of current. The heating effect of current is obtained by the transformation of electrical energy into heat ene…

Electricity is an important source of energy in the modern times. Electricity 🔌 is used in our homes, in industry and in transport. For example, electricity is used in our homes for lighting, operating fans and heating purpose. In industry, electricity is used to run various types of m…

" Where there is oxidation there is always reduction - Chimestry is essentially a study of redox systems. " Chimestry deals with varieties of matter and change of one kind of matter into the other. Transformation of matter from one kind into another occurs through the various …

As already mentioned, the purpose of a communication system is to transmit information or message signals. Message signals are also called baseband signals, which essentially designate the band of frequencies representing the original signal, as delivered by the source of information. N…

What is light? This question has haunted mankind for a long time. But systematic experiments were done by scientists since the dawn of the scientific and industrial era, about four centuries ago. Around the same time, theoretical models about what light is made of were developed. While bu…