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Central Board of Secondary Education, Delhi has been conducting CBSE group Mathematics Olympiad for students studying in its affiliated schools.

WHO CAN PARTICIPATE IN CBSE GROUP MATHEMATICAL OLYMPIAD
a) Student of class XII, XI, X or IX can participate in the competition. However, there will be a common question paper for all participants. Bright students from class VIII may also appear.
b) A school can sponsor maximum five students for the competition.

## The Age of the Universe( Big Bang)

One question has always fascinated the scientists ” When the universe began?” . Current Thinking believes that Universe began as a singularity in space and Time. The singularity is called as Big Bang. It is believed at this time everything was condensed into very small space. After that the Universe has been continuously expansion mode.

A Astronomer Edwin Hubble discovered in 1929 the rate of expansion of Universe i.e the rate at which the galaxies are receding from each other. That law is called Hubble Law. As per Law, if the two galaxies are at distance R,Their present relative velocity of separation is given by

## Energy facts

1)The word energy comes from the Greek word energeia.
2)Most types of energy are either a form of kinetic energy or potential energy.
3)Common examples include heat energy, elastic potential energy, chemical energy, sound energy, nuclear energy, geothermal energy , gravitational potential energy and electric Potential energy
4) Kinetic energy refers to the energy an object has because of its movement. A Truck in motion has kinetic energy, as does a basketball when you pass or shoot it.

## Whats is HOTS(High Order thinking skills)

In Bloom’s taxonomy there are six levels: knowledge, comprehension, application, analysis, synthesis, and evaluation. Higher order thinking skills are those skills in the top three levels: analysis, synthesis, and evaluation. These three skill levels are important in critical thinking

## What are light emitting diodes?

A LED is a forward biased P-N junction diode which emits visible light when energized.

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

1) Appetite is increased in Winters

Atmospheric temperature is reduced in winters but body temperature remains the same.So more heat is lost by the body.So we tend to eat more to make up for the loss

2)The bottom of the cooking utencils is kept black and rough

Black and rough surface absorb more heat from the burner and cooks the food rapidly

## Capacitor : Uses, Unit and Formula

1) The main purpose of the capacitor is to store charge . If an instantanous strong current is to be flown in a circuit,the best way would be to connect the terminals of the circuit to a charge capacitor

2 A capacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary battery. Capacitors are commonly used in electronic devices to maintain power supply while batteries are being changed. (This prevents loss of information in volatile memory.)

## Force on a conductor in presence of an electric field

Force on a conductor in presence of an electric field
In presence of an electric field this surface charge will experience a force. If we consider a small area element of the surface of the conductor then force acting on area element is given by