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### PHYSICS DICTIONARY

Calcination

Process of heating a substance in air or oxygen to bring about changes in physical or chemical constitution like thermal decomposition, phase transition etc is called as Calcination.

(or)

In Solgel method, the term applies to the heating of a polymer network containing metal compounds, to convert it into oxide network.

Calcite

Calcite is also called Iceland spar. Its chemical name is hydrated calcium carbonate. It is a colorless crystal which is transparent to Visible & UV light. It exhibits property of double refraction of light and is uniaxial type.

Calculus

It is the branch of mathematics which focuses on limits, functions, derivations, integrals and infinite series to study the change in function pertaining to physical quantity.

Calorie

Quantity of energy required to heat 1 gram of water through 1o

Calorimeter

Apparatus used to measure amount of heat absorbed or evolved during chemical reaction that is  change of phase or formation of solution.

CAMAC Layout

CAMAC modules are housed in a CAMAC crate, which can accommodate up to 24 normal CAMAC modules. Each module slot is called as station. Besides these 24 stations there is another one reserved for the crate controller module. The controller module is an integral part of the system and cannot be replaced by some other module. Also, some controller modules have double widths and therefore take up two slot positions. In such a case, the crate can accommodate up to 23 normal modules. The back plane of a CAMAC crate is called DATA WAY. DATA WAY consists of not only control, data, and bus lines but also module power lines. These lines are connected to the modules through sockets. There are standard guidelines for the current consumption at these sockets. The current should not exceed more than 3A at any of the sockets. Furthermore the power dissipation per station should not exceed 8W. However this rating can be relaxed in certain situations up to a maximum of 25W. The power rating for the whole crate is 200W.

CAMAC Logic

The CAMAC logic conforms to the standard TTL and DTL series logic with one exception that the signal convention is inverted such that the high state corresponds to logic 0 and low state to logic 1.

CAMAC Standard

CAMAC is an acronym of Computer Automated Measurement and Control. This standard was originally defined in 1969 by the ESONE Committee and was later on jointly standardized by the NIM and ESONE committees. With its built-in controllers and interface capabilities, CAMAC provides a more versatile architecture than NIM, though at the expense of much more complicated and difficult customization. The standard CAMAC backplane is called DATAWAY, which can be directly interfaced to a computer. This feature of CAMAC system makes it far more advantageous over its NIM counterpart where backplane does not have this functionality. In this way one can talk to any module in the crate through simple CAMAC commands without the need to connect it directly to a computer.

Camera

Device equipped with lens for capturing light from objects and forms images on a film or stores in the form of an image digitally. The lenses are made in a wide range of focal lengths. The term camera comes from word obscura (Latin for “dark chamber”) on early mechanism for project images.

Canal Rays

Beams of positive ions created in certain types of gas discharge tubes containing rarefied gas. They were first observed in Crooke’s tube during experiments by German scientist Eugen Goldstein in 1886.

Candela

A unit of luminous intensity equal to 1/60 of luminous intensity per square centimeter of a black body radiating at the temperature of solidification of Platinum (2046 K)

(or)

The candela is luminous intensity in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 Hz and that has a radiant intensity in that direction of 1/683 Watt per Steradian.

Canonical Ensemble

It is a collection of large number of essentially independent systems having same temperature, volume and number of particles.