Jagran Josh Logo
  1. Home
  2.  |  
  3. Science
  4.  |  
  5. Physics

General Knowledge for Competitive Exams

Read: General Knowledge | General Knowledge Lists | Overview of India | Countries of World

Do you know why Oil and Water does not mix together?

Nov 17, 2017
We have seen many times and even we have tried at our homes that when we put oil in water and stir it, eventually they separate in to two distinct layers. Why is it so? Through this article we will study why oil and water does not mix together, why oil is sticky and why oil floats on water.

What is SMOG and how it is harmful for us?

Nov 8, 2017
Smog is derived from two words i.e. smoke and fog which is also described as a mixture of various gases with dust and water vapour and makes breathing difficult. In 17 years such an alarming situation raised in Delhi which raised health emergency. In this article we will discuss about the sources of smog, how it affects our health and how it is formed; what are the necessary precautions that we can take etc.

List of Phenomena related to Sound

Oct 27, 2017
Sound is all around us but do you know what is sound. It is a type of energy made up by the vibrations produced. It travels as a wave through a medium like liquid, solid or gas but it does not exist in a vacuum of space. This article deals with the various phenomena of sound with explanation for better understanding.

What makes diamond shine and sparkle?

Oct 9, 2017
Diamond is the star of jewellery. Being hardest substance it shines and sparkle. It has three dimensional arrangement of carbon atoms linked together by strong covalent bonds. In this article we will discuss why diamond shine and sparkle. Which property makes it shiny etc.

Top 10 countries with largest military expenditure in the world

Sep 27, 2017
The defence budget of US military for the fiscal year 2018 is $ 824.6 billion. This budget has a base budget of $ 574.5 billion for the development of the US Army, whereas $ 64.6 billion is set aside to fight Islamic State and war on foreign lands. America's defence spending is more than the total defence budget of top nine military spenders of the world. India's entire defence budget is $56 billion.

Do you know why Saturn have rings and how they are formed?

Sep 15, 2017
Saturn have rings and is the most striking feature of the Solar System. How many rings Saturn have, of what these rings are made up, Why Saturn have rings, how these rings are formed etc. are answered in this article

5 Facts that you don’t know about the Infinity Symbol

Apr 12, 2017
Various theories or ideas are propounded for the existence of the symbol Infinity but that time it considered as a philosophical concept. This article deals with some facts related to the Infinity symbol like who had discovered this concept, when it was discovered, first time when it was used, how it was used etc.

Why bursting of Balloon makes sound when pricked with a needle?

Apr 11, 2017
Mostly with birthdays and various parties, we see decoration made by colourful balloons which looks amazing and recall the memories of childhood. Have you ever thought why this happens? Why balloon produces pop sound instantaneously rather than leaking air slowly? Let us find out the reason behind it.

List of Important Discoveries in Physics

Mar 3, 2017
Discovery is finding something meaningful that was not of knowledge before. This article deals with various discoveries which is like a new increment to knowledge help in the advancement of mankind like production of crop, medical applications etc.

What is an Interceptor missile and how it is useful

Mar 2, 2017
The interceptor missile is an anti-ballistic missile (ABM) which is a surface-to-air missile designed to counter ballistic missiles like intermediate range and intercontinental ballistic missiles launched from any country. It is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. How interceptor missile works and how it is useful is discussed in this article.

National Science Day a discovery of Raman Effect

Feb 28, 2017
National Science Day is celebrated all over India on 28 February to mark the discovery of the phenomenon of Raman Effect by CV Raman in 1928 and for his remarkable discovery in 1930 he got Nobel Prize which was the first Nobel Prize for India in the field of Science. This article deals with why National Science Day is celebrated, how it is celebrated, when it is celebrated, its objectives behind the celebration etc.

How ISRO’s 104 Satellite launch can be a remarkable history

Feb 13, 2017
Till now ISRO has launched maximum 20 satellites at one go; it was PSLV-C34 on June 22, 2016. But now ISRO is going to create a history by launching 104 satellites on board, a flight of Polar Satellite Launch Vehicle (PSLV) on 15 February 2017 from Sriharikota spaceport in Andhra Pradesh. Let us find out how this is possible and what all satellites are going to be launched by ISRO.

Do you know that our moon is made up of 20 smaller moonlets?

Jan 17, 2017
As, compared to other planets of the solar system, the moon is the only planet that glaze. Origin of the moon is always full of mysteries. Scientists from several years are constantly trying to find out the secrets, and in order to it the current Israeli scientists have claimed that the origin of the moon is due to the merging of 20 smaller moonlets. In this article we will see some facts related to it.

Summary on Work, Power and Energy

Dec 13, 2016
Work is done when a force produces motion. And for doing work energy is required. This energy we get from the food which we eat and if work is done by machine, then energy is supplied by fuels or by electricity. This article deals with the summary of Work, Power and Energy, its mechanism, formulas and how they are related to each other in a crux form which not only clear your concepts but also help in your preparation and in solving problems.

Do You know that who Invented Ball pen?

Sep 29, 2016
The inventor of ball pen was Ladislao José Bíro, a Hungarian born in 1899 into a Jewish family. He invented the ball pen in 1931 to get rid of fountain pen's blotting and smudging.

Space Missions to the Sun: Brief Analysis

Aug 26, 2016
The Sun is the star at the centre of the solar system. It is mainly composed of hydrogen and helium. There are various solar missions launched by observatories to study high resolution and close-up view of Sun and its inner heliosphere (the innermost region of our Solar System) to predict and to better understand the intractable or restive behaviour of the star on which our lives depend.

“General Science” A Complete Study Material

Jun 6, 2016
The Complete Study Material of “General Science” i.e. Physics, Chemistry and Biology is given in a compiled form that will be very helpful for the students of 6th to 12th class, undergraduates and those who are preparing for competitive exams familiar with the diversity of the subject and make them understand the concepts.

Thermal Expansion of Solids, Liquids and Gases

Mar 23, 2016
The change in temperature of a body causes expansion or contraction of that body. Most of the substances expand on heating and contract on cooling. This is called thermal expansion. It is interesting to know why the level of mercury rises with temperature, wires attached to electric poles contract or expand with change in season, etc. This all is due to thermal expansion.

Mechanical Properties of Fluids

Mar 21, 2016
Some liquids show resistance to motion and it is like internal friction. This is called viscosity. Liquids acquire a free surface when poured in a container. The additional energy that these surfaces have is called surface tension.

Sound: Doppler Effect and Echo

Mar 11, 2016
Sound is a form of energy. It is that form of energy which makes us hear. Sound wave is a vibratory disturbance in a medium which carries energy from one point to another without there being a direct contact between the two points. According to Doppler Effect the frequency of sound wave changes with motion, either of the source or of the observer. The reflection of sound wave is called echo. It varies in different mediums.

Refraction of light by Spherical Lenses

Mar 1, 2016
Refraction is the change in direction of light when it passes from one medium to another. The working of a lens is based on the refraction of light when they pass through it. Lens is a piece of transparent glass bound by two spherical surfaces and is used to magnify objects. They are of two types convex and concave. The image produced by convex lens is enlarged and the image produced by concave lens is diminished.

Refraction of light through a glass prism

Feb 25, 2016
Refraction is the bending of light when it goes from one medium to another so, when a ray of light passes through a glass prism, refraction of light occurs both, when it enters the prism as well as when it leaves the prism. Since the refracting surfaces are not parallel, therefore, the emergent ray and incident ray are not parallel to one another. In this case the ray of light is deviated on passing through the prism.

The Human Eye and its defects

Feb 25, 2016
The Human eye works on the refraction of light through a natural convex lens made up of transparent living material and enables us to see things around us. Also, the ability to see is called vision, eyesight or drishti. Sometimes a person cannot able to see distant or nearby objects clearly and have a defect of vision which can be fixed by wearing spectacles.

The Universe: Stars, Sun, Asteroids..in a nutshell

Feb 24, 2016
The Universe is everything we can touch, feel, sense, measure or detect. It includes living things, planets, stars, galaxies, dust clouds, light, and even time. All the existing matter and space as a whole is considered as universe. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies each containing millions or billions of stars.

The Solar System and Satellites

Feb 24, 2016
The Solar System consists of the eight planets that orbit our Sun and other celestial bodies such as moons, comets, asteroids, minor planets, and dust and gas. Sun is considered as the centre of the solar system and all the planets revolve around the sun. The eight planets in the solar system in the increasing order of their distance from the Sun are Mercury, Venus, Earth and Mars, Jupiter, Saturn, Uranus and Neptune.

Resistance of a Conductor

Feb 17, 2016
Resistance is the hindrance to the flow of electric charge. The obstruction posed in the way of current carrying particles by fixed particles creates resistance in an electric circuit. The measurement of the electric current in an electric circuit therefore, depends on two factors primarily i.e. Potential Difference across the ends of the conductor and Resistance of the conductor. The relationship between current and potential difference is also explained by Ohm’s Law.

Refraction of Light

Feb 16, 2016
Refraction of light takes place when light travels from one medium to another. It takes place at the boundary between the two mediums. Also, we know that speed of light is different in different mediums. So, it occurs due to the change in speed of light on going from one medium to another.

Reflection of light from Spherical Mirrors

Feb 12, 2016
A spherical mirror is that mirror whose reflecting surface is the part of a hollow sphere of glass. Spherical mirrors are of two types: concave mirrors and convex mirrors. In a concave mirror reflection of light takes place in the bent in surface or concave surface. In a convex mirror the reflection of light takes place at the bulging-out surface or convex surface.

Reflection of Light

Feb 12, 2016
Light is a form of energy which enables us to see objects and the straight line along which it travels is called ray of light. Reflection of Light is the process of sending back the light rays which falls on the surface of an object. The image formed due to reflection of an object on a plane mirror is at different places.

Magnetic effects of Electric Current

Feb 10, 2016
A current carrying conductor creates a magnetic field around it, which can be comprehended by using magnetic lines of force or magnetic field lines. Magnetic field in a current carrying straight conductor is in the form of concentric circles around it. The direction of magnetic field; in relation to direction of electric current through a straight conductor can be depicted by using the Right Hand Thumb Rule which is also known as Maxwell’s Corkscrew Rule.

12 Next   

Latest Videos

Register to get FREE updates

    All Fields Mandatory
  • (Ex:9123456789)
  • Please Select Your Interest
  • Please specify

  • By clicking on Submit button, you agree to our terms of use
  • A verifcation code has been sent to
    your mobile number

    Please enter the verification code below

Newsletter Signup
Follow us on