WHAT WOULD HAPPEN, IF THE SUN WERE MADE OF BANANAS!


The sun is hot, it is because its enormous weight creates vast gravity putting its core under colossal pressure, just as a bicycle pump gets warm when you pump it, the pump increases the temperature. Enormous pressure leads to enormous temperature. If instead of hydrogen, you get a billion billion billion tons of bananas and Read More

Thermal power plant


A Power plant in which the heat required to make steam to drive turbines (to make electricity) is obtained by burning fuels (coal, oil or gas) is called thermal Power plant. Coal (fuel oil or natural gas) is burned in a furnance F to produce heat. This heat boils the water in boiler B to Read More

MAGNET


A magnet is an object which attracts pieces of iron, steel, nickel and cobalt. One of the most common magnets is the bar magnet. A bar magnet is a long, rectangular bar of uniform cross section which attracts pieces of iron, steel, nickel and cobalt. Properties of Magnet A magnet has two poles near its Read More

MAGNETIC FIELD LINES


A magnetic field is described by drawing the magnetic field lines. The magnetic field lines are the lines drawn in a magnetic field along which a north magnetic pole would move. The magnetic field lines are also known as magnetic lines of force. The direction of magnetic field line is the direction of force on Read More

RESISTANCES (OR RESISTORS) IN PARALLEL


The reciprocal of the combined resistance of a number of resistance connected in parallel is equal to the sum of the reciprocal of all the individual resistances. For ex. If no. of resistances are connected in parallel then their combined resistance R is given by formula When a number of resistances are connected in parallel Read More

NEWTON’S FORMULA:


If the distance of object and image are not measured from optical centre (C), but from first and second principal foci respectively, then newton’s formula states Where, distance of object from first focus F1. distance of image from second focus. If medium on either side of lens is same, then . So, Newton’s formula takes Read More

POWER OF A LENS


“Power of lens is a measure of the convergence or divergence, which a lens introduces in the light falling on it.” It is defined as the tangent of the angle by which it converges or diverges a beam of light falling at unit distant from the optical centre. Thus, Power of a lens is the Read More

TOTAL INTERNAL REFLECTION


When a ray of light travels from an optically denser medium to a rarer medium, the refracted ray is bent away from the normal e.g the incident ray ‘AO1’ is partially reflected (O1C) and partially refracted (O1B), the angle of refraction being larger than the angle of incidence. As the angle of incidence increases, the Read More

SIGN CONVENTION OF A LENS


We follow new Cartesian sign conventions. (a) The distance always measured from optical centre. (b) The distance measured to the right of the optic centre is taken as positive and to the left is negative. (c) The height measured vertically upward is positive whereas vertically downward is negative.