# Knowledge Pays Off (SANCHAY)

What is the name of virus that causes bird flu?
The virus responsible for causing bird flu is H5N1

What is the law of averages?

The law of averages deals with the probability of occurrences in the long term in which one will neither win nor lose all the time.  For example, if it rains every day this week, by the law of averages we’re bound to get a sunny day soon. This colloquial term is a popular interpretation of a statistical principle, Bernoulli’s Theorem, formulated in the late 1600.

How is zero gravity simulated?

Simulation of zero gravity while still within the pull of the earth’s gravity is achieved in a similar manner to that of a man-made satellite. When a body moves in a circular path, it experiences a centrifungal force acting on it. This force points radially outwards and depends on both the speed and the radius of trajectory. Given this factor, if a plane flies in a circular arc trajectory, then passengers experience a centrifungal force pointing away from the earth. At a certain velocity, this force exactly counterbalances gravity, and passengers experience weightlessness or zero gravity.

Which other countries celebrate their independence day on August 15?

Korea, Congo, Liechtenstein and India celebrate their Independence Day on August 15. On August 15, 1948, the Republic of Korea was established south of the 38th Parallel. August 15 is celebrated as Liberation Day in Korea. On August 15, 1960, the Republic of Congo (Brazzaville) declared its independence from France. Also, Liechtenstein Day is celebrated on August 15.

Why is diesel cheaper than petrol?

Diesel is not cheaper than gasoline or petrol in all European and North American countries. In fact,  it is generally more expensive compared to gasoline. Diesel is cheaper in India because it’s believed to be generally used by farmers and truck and bus fleets (local and inter-city buses owned by state governments). It was also believed that gasoline is used by cars and motorcycles once considered luxury vehicles. Thus, to reduce the burden on farmers and truck and bus fleet operators, diesel is priced lower than petrol in India.

How do astronauts communicate in space?

Sound cannot travel through the vacuum of space, but visible light and other forms of electromagnetic radiation can, one of
which is     radio. Astronauts have devices in their helmets which transfer the sound waves from their voices into radio waves and transmit them to the  ground (or other astronauts in space). This is how a radio at home works ––  radio waves are often thought to be a form of sound but they are not sound waves. They are a form of electromagnetic radiation, analogous to visible light, and therefore can propagate through vacuume. These are then transformed into sound.

How many satellites are currently revolving around the earth?

Although anything in the Earth’s orbit is technically called a satellite, the term is typically used to describe a useful object placed in orbit purposely to perform some specific mission or task. Approximately 23,000 items of space junk objects that were inadvertently placed in orbit or have outlived their usefulness are floating above the Earth. The actual number varies depending on which agency is counting. Payloads that go into wrong orbit, satellites with run-down batteries , and leftover rocket boosters all contribute to the count. This count is almost 26,000.

Which country has the oldest flag?

The country with the oldest flag in the world is that of Denmark. The Danish flag, called the Danneborg, dates back to 13th century A.D. It is believed to have been in existence since june 15,1219 though it was officially recognised as the national flag in 1625. Flags, themselves date further back. Crude flag-like vexilloids were used in Ancinet Egypt around 3400 B.C.. The first modern flag was the Dutch prinsenvlag ; it is no longer in use.