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Firstly Blackhole is not is hole.
It is a neutron star.

A Black hole formed when a star dies. The dead star firstly expand due to supernova and then squeeze or contract toward its core due to its high gravitational pull.
Due to this high contraction the electrons of atoms come near to protons in nucleus and become neutral. So that it is called neutron star.

This information is based on some famous theories.
According to some theories the size of a black hole can be as small as just one atom and big as 75 billion miles in diameter.

Currently the smallest known black hole is only 20 km in diameter and have mass equivalent approximetely 3.4 solarmass.
(1 solarmass= 1.8×10³⁰kg).

One teaspoonfull of black hole matter has equivalent mass of one earth. Because it is so dense.

The spin of black hole on its axis is nearly 3000 times faster then earth.
The inside temperature of black hole is very low about 1/10¹⁴kelvin while the outside temperature is very high.

The gravitational pull of black hole is very high. So it bends the space. Due to this bend in space, even light can not pass through a black hole (because light has the property to the travel in straight line).

Anything can never be fall in black hole directly. Due to black hole’s high spin, the object that fall in black hole rotate with a very high speed around it.

Even everything not fall in the black hole because due to high spin, and because of this the centrifugal force increases.
Due to increment in centrifugal force some mass can escape the gravitational pull of black hole.

If anything falls in blackhole, the body rotating and start to stretch toward its surface.
The body Stretch because gravity attract it toward the surface and high spin and high centrifugal force oppose this attraction. So both the phenomena of moving and attracting occur at same time and then the body get stretched.
Because of these phenomena, the form of body changes and it cannot remain stable.

If you fall into a blackhole, the time moves slowly for you due to bend in the space.

Mostly every galaxies has black hole in middle. Our galaxy(the milky way) also has a giant black hole in its middle.

Black holes cannot be observe or seen directly because they are black. They are observed by the radiation and stars moving around them.

Nearest found black hole to our solar system is HR 6819 and it is only 1000 light year away.
(Light year is the distance that travelled by light in one year with speed 3 lakh km/sec).

To come out from a black hole as impossible as to climbing on a waterfall from bottom to top by a boat.

to be continue……..

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Graphic representation of trophic structure and function of an ecosystem, starting with producers at the base and successive trophic levels forming the apex is knows as an ecological pyramid.

  1. Pyramid of numbers: It is based upon the total biomass (dry matter) at each trophic level in a food chain. The pyramid of biomass can also be upright or inverted.3.5
  1. Pyramid of biomass: It is based upon the total biomass (dry matter) at each trophic level in a food chain. The pyramid of biomass can also be upright or inverted.3.6
  1. Pyramid of energy: The amount of energy present at each trophic level is considered for this type of pyramid. it is always upright. 3.7



Below 100 kev •It is the emission  of electrons or other free carrier  when electromagnetic  Radiation  like visible light, x rays, y rays hits a material, electrons emits electrons. •Photon transfer all its energy to one of orbital electron of the atom. •Absorption of electron by atom leads to ionization by emission of electron  •Electron acquire kinetic energy of amount equal to that of photon  energy •Electron released in this called photoelectron.


•Produced by transition of electron from the outer to inner orbit of the atom (k&m shell)

For transition

•For transition of electron, it is necessary to create vacancy or a hole in inner orbit. •Once vacancy is created in inner shell of atom, electron from the outer shell falls to fill the vacancy. •Potential difference between potential energies of shell in transition is emitted as electromagnetic radiation called characteristic radiation of atom.

•Vacancy in k shell = K x ray •Vacancy in L shell = L x ray •If vacancy  created in k shell- filled by L shell •Difference between two energy eL –eK =  [-63-(-1072)] •Energy emitted as k x ray =1009 ev.


•Radiative collision between electron and nucleus •when electron passing near nucleus suffer a sudden deflection and acceleration by a coloumb force of attraction. By the electron lose their K.E in the form of bremstrahlung x ray.

   also called braking radiation. •Amount of radiation production determined by distance between bombarding electron and nucleus Production increase with accelerating voltage and atomic no. of target material.


•Photon energy >1.02 mev passes close to the nucleus of an atom. •It interacts with the nucleus and emission of the positron (e+) and electron is ejected. k/a pair production. •The positron loose its energy after interacting with the electron and liberate annihilated photon of energy 0.51 mev in opposite direction. It is called annihilation process •Reason behind photon move in opposite direction is conserve momentum as they move at 1800


•Nuclear process, energy of incident photon is more than >7mev •Photon enters to the nucleus and the particle (n+, p+, alpha particle) are emitted.




The world health assembly is the supreme  decision making body for WHO.

It generally meets in Geneva in may each  year, and is attended by delegations from all  194 member states.

ØThe health assembly appoints the  Director-General. The current director

general of WHO is Dr. Tedros Adhanom  an  Ethiopian nationalist, who started his 5 year term on 1st July 2017.


  1. To determine international health policy and  programme.
  2. To review the work of past years 
  3. To approve the Budget.
  4. To elect member state to designate a person to  serve for 3 years on executive board.
  5. supervises the financial policies of the  organization and reviews and approves the  proposed program budget.


“The attainment by all people the highest  level of health”.


“To lead strategic collaborative efforts among  Member States and other partners to promote  equity in health, to combat disease, and to  improve the quality of, and lengthen, the lives  of the all peoples of the world”.




this month is the first anniversary of PENSER and we congratulate our viewers on this anniversary.

last year is great for PENSER and it’s just because of our viewers. we’re glad that we got such an amazing and beautiful audience who loved us unconditionally

our audience gifted us 100k views and we are thankful for this. this is really an incredible gift ever.

PENSER is now a very big educational website. it has more than 200 articles on 15+ topics and 100000 views with 1.7k subscribers.

on last year we didn’t think that one day it would be so famous. but as we know great power comes with great responsibility. now viewers wants more and they have faith on us and we promise that we’ll give better information on some interesting topics

in last thank you all of you for making it successful.






The World Health Organization is a  specialized agency  of United Nations. WHO was established on 7th April 1948. The headquarters of WHO is located in  Geneva. WHO serves as the directing and coordinating  authority for International health matters and  public health.


First global health organization. In latter half  of 19 th century, severe cholera epidemics  was occurred. At that time, series of  international sanitary conferences were held  in Europe to co-ordinate policy & practice  around quarantine & disease management. The League of Nations established a health  organization in 1920.


Establishment of the United Nations is in  1945, marked as a period of aggressive  internationalism & international  organization building & though health was  not initially thought to be under the U.N.

After its motion started by Brazilian &  Chinese delegates to establish an  international health organization and that  was generally accepted.

A group of health experts, working on emergency  relief in World War II were charged with the task of  drafting a constitution to define the structure &  mandate of the body that would become known as  the World Health Organization  (WHO).

Finally, WHO’s constitution came into force on 7 th  April 1948. This date celebrates every year as “ WORLD HEALTH DAY” by all over world.


To develop & implement multisectorial public  policies for health, integrated gender- & age-  sensitive approaches that facilitate  community empowerment, together with  action for health promotion, self-care &  health protection throughout the life course  in cooperation with the relevant national and  International partners.






Scattering – in this x ray interact with matter

Elastic collision – in elastic collision  total kinetic energy of the body remains same

Photon energy = < 10 kev.

X ray photon passing close to the atom cause electron to vibrate at equal frequency  to the incident radiation. •

Wavelength remaining  same as of incident photon to that of emitted photon.


•Single electron involved •No ionization


•All the electrons of an atom. •It is the phenomenon of scattering  of photon particle by the molecule of gas, multiple interaction of incidence radiation to electron of atom.


Inelastic collision • High energy photon (100kev or more) •Incident photon loose energy and its gain by the scatter radiation •Amount of energy gain by electron and loose by incident  photon are depend upon angle of scatter and energy of incident photon •Larger angle of scatter of photon, more energy loose to electron. (max 180°) back scatter. •E0 = E2 + E3.


•Below 100 kev •It is the emission  of electrons or other free carrier  when electromagnetic  Radiation  like visible light, x rays, y rays hits a material, electrons emits electrons. •Photon transfer all its energy to one of orbital electron of the atom. •Absorption of electron by atom leads to ionization by emission of electron  •Electron acquire kinetic energy of amount equal to that of photon  energy •Electron released in this called photoelectron.




Article by – penserstudypoint

The asteroid belt is a large disc-shaped ring with large solid bodies such as asteroids (minor planets).

It divides the sequence of eight planets into two parts.

The four planets are before the asteroid belt towards the Sun are Mercury, Venus, Earth and Mars and the four planets are ahead of the asteroid belt are Jupiter, Saturn, Uranus and Neptune.

Size of asteroid belt:-

The asteroid belt is about 150 million km thick and approximately 2.2 AU from the sun.
The estimated mass of the asteroid belt is 2.39 × 10²¹ kg while only mass of the Earth is larger than the mass of the entire asteroid belt and is about 5.9×10²⁴kg .

Materials in asteroid belt:-Most of the asteroid belt material was already lost during the early 100 million years of the solar system.

It mainly consists of three types of bodies in which the first type is C-type that are rich in carbon, the second type of bodies are S-type which is silicate rich body and the third type consists of M-type bodies which contain metals like iron and nickel.

The asteroid belt consists of about 1-1.7 million asteroids in a small area of 1 km or more in diameter and this data was traced by infrared wavelengths.

The asteroid belt has large bodies whose size is about 950 km and as short as dust particles.
There is also a dwarf planet named Ceres in the asteroid belt.
There are about 200 known asteroids have a diameter of more than a hundred kilometers in size.

Facts:-Meteroids entering the Earth’s atmosphere are also mostly from the asteroid belt. Meteroids are large bodies made up of ice and dust particles.

There is also a dwarf planet named Ceres in the asteroid belt


The Internet is the largest computer network in the world. It links millions of smaller networks which are connected to each other by phone lines, cables, or wireless connections.

If your computer is connected to the Internet, it can help you to get information from other computers, send messages to a friend who lives far away, or do lots of other amazing things like hear a song, or watch a famous movie.

This is possible because when you log on to the Internet, you are given access to the other computers that are also connected.

Today, people rarely write letters- they send e-mails instead. Electronic mail or e-mail, is a method of using your computer to send messages to other people who are connected to the Internet via their computers. Your message is first delivered to a computer called the mail server.

From there, it is transferred through the net, until it reaches its destination Just as you need to know a person’s address to send a letter, you have to know a person’s e-mail address to send an e-mail.



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Fire is a chemical reaction that occurs very quickly, and in the process, gives off heat and light.

Three things are necessary for this reaction to occur- fuel, oxygen, and heat.

Fuel whether it is paper or wood-by itself will not catch fire. It is only when the fuel is heated, and becomes hot enough, that the oxygen in the air combines freely with it to burst into flames.

The reason, fire is hot is because it releases a lot of energy that has been stored in fuel. For example, energy from sunlight is stored in the wood that is used as fuel.

When energy is released very quickly, heat and light are produced.

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