flow objects

When an object moves through a fluid, there will be friction due to the resistance of the material medium. This resistance increases with the velocity of the body as in the case of a rocket and aeroplane. Hence to minimize this friction due to the resistance of the medium, the bodies of ..

Heat energy is present in every object above absolute zero. How do we know that heat is present in every object? Temperature of the body is an indication. (Absolute zero is the lowest temperature possible and is equal to -273 o C). Are heat and temperature one and the same? No. ..

Static electricity was known to people more than 2500 years ago. The Greeks knew about the attractive property of the resin amber. They knew that by rubbing amber with cloth, it could be made to attract small feathers. The Greek name for amber was 'elektron'. After about a thousand years William Gi..

During thunderstorms, large amount of electrical charge separation takes place in the clouds. As a result, some regions of the cloud have overall positive charge, while others have overall negative charge. When this separation becomes sufficient, the air ionizes and becomes conducting. This results..

The following figure shows a copper voltameter with copper electrodes. Current starts flowing in the circuit when the key is closed. Copper is removed from the anode and gets deposited on the cathode. The passage of current through the electrolyte is causing a chemical change. These chemi..

Many cameras have built in exposure meters, having light sensitive surfaces. A current flows in the meter depending on the amount of light falling on it. So, the photographer has to adjust a suitable set of aperture and exposure times for correct exposure. There is also another aspect cal..

When the sphere is connected to a conducting wire it gets earthed and the electrons flow to the ground and the positive charge remains there due to the attractive force of the external charge. When the external conductor is removed, the positive charge remains in the sphere making it a po..

The Sun - The sun is at the center of the solar system. Its mass is about 740 times as great as that of all the planets combined. The huge mass of the sun creates the gravitation that keeps the other objects traveling around the sun in an orderly manner. Sun The sun is a typical star, of ..