measuring position: percentiles

To determine the position of an object, we must be able to see the object. This can be done with the help of light of suitable wavelength. When a beam of light falls on an object, the photons of this incident light are scattered by the object and the reflected light enters our eye. Now, i..

Following sign convention is used for measuring various distances: All distances on the principal axis are measured from the optical centre. The distances measured in the direction of incident rays are positive and all the distances measure..

The physical meaning of entropy is that entropy is a measure of degree of disorder (or randomness) of a system. The relation between entropy and disorder provides a suitable explanation for entropy change in various processes. The greater the disorder in a system, the higher is the entro..

= 0.01 cm The Vernier calliper consists of a main scale fitted with a jaw at one end. Another jaw, containing the vernier scale, moves over the main scale. When the two jaws are in contact, the zero of the main scale and the zero of the vernier scale should coincide. If both the zeros do not coinci..

Moseley had done experiments on the characteristic X-rays and this led to the development of the concept of atomic number. The periodic table was made according to the atomic weight in earlier days. But some anomalies were found in such an arrangement. Moseley measured the frequencies of ..

Following sign convention is used for measuring various distances during the formation of images by lenses: All distances on the principal axis are measured from the optical center. The distances measured in the direction of incident rays are posit..

In a Rectangular Cartesian System of coordinates the position of a point in a plane is determined by an ordered pair whose elements give the distances from the intersecting straight lines at right angles to each other. These lines are called the axes. The vertical line is called the Y-a..

When substances like glass and silk or ebonite and fur are rubbed, positive and negative charges of equal amount are simultaneously produced. Like charges repel, unlike charges attract. Electroscope is the device used for detecting the charge on a body. The divergence of the leave..

The position of the point P in a plane in the rectangular co-ordinate system is determined as follows: Draw PA and PB perpendicular to XX' and YY'. The segment OA = a measures the distance along the x-axis (the x-coordinate and the perpendicular distance AP = OB = b ( paralle..

If a ray rotates about the starting initial position, in anticlockwise direction, comes back to its original position after 1 complete revolution then it has rotated through 360 o . 1 complete rotation is divided into 360 equal parts. Each part is 1 o . Each part (1 o ) is divid..