## JEE Mains के लिए Physics की best Books

JEE Mains के लिए Physics की best Books

1. NCERT PHYSICS

2. Concept of physics

3. Understanding physics

4. Physics – B.M Sharma

5. Previous Year

JEE Mains के लिए Physics की best Books

1. NCERT PHYSICS

2. Concept of physics

3. Understanding physics

4. Physics – B.M Sharma

5. Previous Year

According to Torricelli’s theorem -The velocity of efflux of a liquid issuing out of an orifice is the same as it would attain if allowed to fall freely through the vertical height between the liquid surface and orifice .

velocity of efflux v = ( 2gh )1/2

Note – The velocity of efflux is the velocity of escaping liquid relative to the container (but not necessarily relative to ground when the container moves ) .

If the velocity of a liquid (or gas) of density p coming out through an opening of area of cross section a is v, then there will be a thrust force F = ρav² due to liquid coming out the opening. The direction of the thrust force will be just opposite to the velocity direction .

There are various applications of Bernoulli’s Equation ( Theorem ) – pitot tube , Atomizer , siphon tube , lifting of aircraft, Blowing off the roof during wind storm , Venturimeter , Magnus effect , Velocity of efflux etc .

According to Bernoulli’s theorem, the sum total of these three kinds of energies, kinetic energy, potential energy and pressure energy remains constant along a streamline in a steady flow of an ideal fluid. That is

P + ρv²/2 + ρgh = constant

Johannes Kepler used empirical observations, and sophisticated calculations to arrive at the famous Kepler’s laws of planetary motion, published in 1609 and 1619. What is particularly significant about Kepler’s laws is that they challenged the prevailing world’s view, with the Earth in the center of the universe (a geocentric theory) and the Sun and all the planets and stars orbiting around it, just as the Moon does .

A Black hole is a place in space where gravity pulls so much strong that neither a particle nor electromagnetic waves like light can escape from it .

There are four types of black holes – Stellar , Intermediate , Supermassive and Miniature

The quantities which do not depend upon other quantities for their complete definition are known as fundamental quantities.

There are 7 fundamental quantities .

eg- length , mass , current etc .

and Derived quantities are those quantities that can be expressed in terms of fundamental quantities .

eg- density , velocity , momentum , energy etc .

The continuity equation is a mathematical expression of the law of conservative of mass in fluid dynamics .

This equation defines the steady flow of a fluid in a tube. It states that if flow of a fluid is steady then the mass of the fluid entering per second at one end is equal to the mass of fluid leaving per second at the other end .

We know that in an statics fluid pressure in horizontal direction will be constant because of equi-pressure surface but in case of vertical Variation it’s Vary .If the weight of the fluid can be neglected, the pressure in a fluid is the same throughout its volume. But often the fluid’s weight is not negligible and under such condition pressure increases with increasing depth below the surface .

dp/dy = ρg . ( This is the general expression of variation of pressure with depth ) .