Physics Test - 5

Magnetic flux: The number of magnetic field lines passing through a surface area normally is called magnetic flux. It is denoted by \(\phi\). 

Magnetic flux is mathematically equal to the dot product of the magnetic field and area vector through which it is passing.

\(\Rightarrow \phi=\vec{B} \cdot \vec{A}=B A \cos \theta\)

Where \(B=\) magnetic field, \(A=\) area vector, and \(\theta=\) angle between \(B\) and \(A\)

The SI unit of magnetic flux is weber (Wb).

A body moving at constant speed in a circular path experiences an acceleration directed towards the center of the circular path. This acceleration is called centripetal acceleration and is provided by a centripetal force. In the circular motion situation, even if the speed is constant the acceleration changes all the time as the direction keeps on changing.

Max Planck first gave the Quantam Theory

Gamma rays were first observed in 1900 by the French chemist Paul Villard when he was investigating radiation from radium.

Albert Einstein stated the equation  E = mc^2..As a physicist, Einstein had many discoveries, but he is perhaps best known for his theory of relativity and the equation E=MC², which foreshadowed the development of atomic power and the atomic bomb

Anemometer is a measuring instrument used in meteorology to measure wind speed. The first anemometer was invented by Leon Battista Alberti in 1450.

Electricity is measured in units of power called Watts, named to honor James Watt, the inventor of the steam engine. A Watt is the unit of electrical power equal to one ampere under the pressure of one volt. One Watt is a small amount of power.

A black hole is a region of space from which nothing can escape, according to the general theory of relativity, it is the result of the curving of spacetime caused by a huge mass. Around a black hole there is a position of no return, called the event horizon.A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes. They are invisible.

A boat will float when the weight of the water it displaces equals the weight of the boat and anything will float if it is shaped to displace its own weight of water before it reaches the point where it will submerge. Floating of the boat works on the principle of buoyancy force which is an upward force exerted by a liquid, gas or other fluid, that opposes the weight of an immersed object.  In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the column than at the top. This difference in pressure results in a net  force that tends to accelerate an object upwards.

Light Year is a unit to measure distance.