 Name: KEYISIELUNGBE
DoB: 15/07/1994
Sex: Male
Edu. Qualification: B. Sc (Physics), M. Sc (Regular)
Teaching experience: 2 years
Address: Ko

Keyisielungbe Zeme

In this Course, the educator discusses Astrophysics deals with astronomy and astrophysics.

CBSE Class 12

English

Astrophysics: CBSE Class XII

Crash Course

Physics

Class 6-12

Become a topper in your school and ace your board exams by learning from best educators in the country

CBSE

CBSE (Central Board of Secondary Education)

Different motions of Earth
1. Rotation
2. Revolution
3. Perihelion Change
4. Eccentricity Change
5. Tilt Change
6. Precessional Motion

Different Motions of Earth

Seasons
Why does season change? How? What is the reason? Because of various reasons:-
1. Earth's Tilt
2. Sun Rays inclination
3. Earth's inclination
Various positions of Earth:-
1. Summer Solstice
2. Winter Solstice
3. Autumnal Equinox
4. Spring Solstice

Seasons

Astronomical scales
1. Astronomical Distance
2. Dimensions of Astronomical objects
3. Apparent and Absolute Magnitude
4. Luminosity and Radiant Flux

Astronomical Scales

Milky Way Galaxy is our home galaxy which consists of four major arms and a massive Black Hole called Sagittarius A* at the nucleus. 10-12 Billion years of age and about 10000-18000 light years in diameter. Apart of Local Group of Galaxies and is a Barred Spiral type of Galaxy.

Milky Way Galaxy

Dark Energy
It's an unknown form of energy yet to be detected in the lab but is speculated to exist through some convincing evidences like the CMBR, through the study of Type 1a supernovae explosion and the abundance of it. It does not interact with any fundamental forces except gravity and is sparsely dense.

Dark Energy

A hypothetical and unknown matter which is making up a huge part of mass-energy in our observable universe. It is not detectable because of it's non-interactive property with any electromagnetic radiation but its existence is evident from its gravitational effect on visible matter and gravitational lensing.

Dark Matter

Comets are small extraterrestrial bodies composed of frozen mass and travels around the Sun in a highly elliptical orbit. They have nucleus, coma and tail structurally.  Periodic, Non-periodic, Single Apparition comets, main-belts comets are some of the different types of comets.

Comets

Asteroids are believed to have formed 4.6 billion years ago. They are numerous small celestial bodies composed of rock and metal that move around the Sun mainly between the orbit of Mars and Jupiter. Classifications are based on their Spectra and Albedo, also on their location in the Solar System.

Asteroids

Meteoroids, Meteors and Meteoroids. Meteoroids are those extraterrestrial bodies which travels in space mainly originating from Asteroids, Moon and Mars. Meteors are those that reach reach the atmosphere of Earth and Meteorites are those meteors that reach the surface of Earth.

Meteoroids

There are about 100billion(approx) galaxies in the universe. The galaxy is a large collection of large number of stars,gas and dust held together by gravity.

Galaxies

Stellar evolution is the life cycle of Stars. From the pre-mordial H condensation - proto-star - main sequence stage - Red giant stage - either white dwarf or Neutron star or black hole.

Stellar Evolution- I

Stellar evolution-II
Stable condition is possible only for core of stars having mass upto 1.4  times the mass of the Sun which is called as Chandrashekhar Limit. So for smaller core they end up as White Dwarf but if the core exceed the Chandrashekhar Limit they end up with violent explosion and becoming either as Neutron star or black hole.

Stellar evolution-II

Binary Stars
The system of two stars revolving around each other with a common centre of mass. The less mass star usually revolves around the more mass star. There are 85-90% stars are discovered to have binary partner. Their motion is governed by the Kepler's third law for two bodies. There are 4 types: Visual, Spectroscopic, Eclipsing, X-RAY binaries.

Binary Stars

The star our Sun is an average star which is about 4.5-5 billion years. It consists of 74%H, 25% He and 2% metals. It has four major layers outermost to innermost we have Corona, Chromosphere, Photosphere and the core.

The Star Sun

Solar System
Objects bound by the Sun's gravity consist the solar system. It has 8 planets, dwarf planets, Asteroids, Comets & Meteors.

Solar System

" Arjun Thori "
Education: 12th (Merit Holder), Pursuing B.Tech  (Civil Engineering) | Android App : ARJUN CLASSES | YouTube : MiniSchool 

Arjun Thori

In this course i will teach - Important short & long answer Questions with proper solution for class 12th board exam.

(Hindi) Chapter - Gauss's Law and It's Application : Important Question and Answer - Class12

BSc. maths, Having more than 5 years teaching Experience. And 2 years YouTube teaching Experience.
  I am excited to teach unacademy plus

Udit Yadav

(Hindi) Electric Conduction and Ohm's Law: Class 12

I have graduated(physics) from SDNB Vaishnav college, chromept. And I am quite good in art.And I am much more interested in teaching. 

Kasthuri Ramachandran

The course covers Relation between The Elastic Moduli, Torsion Oscillation Of a Body, Rigidity Modulus By Torsion Pendulum , Maxwell's Needle, and Problems Under Torsion.

Torsion: Class 12 NCERT

The Course covers about Viscosity, Poiseuille's Formula for the flow of liquid through a capillary tube, Poiseuille's Method for determining coefficient of viscosity of liquid, Poiseuille's Method for determining coefficient of viscosity of liquid (variable pressure head)and about Friction and Lubrication.

Lessons

15 lessons • 3h 8m