Temperature of the Sun and Solar Constant If R is the radius of the sun and T is the temperature, then the energy emitted by the sun per second through radiation in accordance with Stefan’s law be given by P = AσT⁴ = 4πR²σT⁴. By the time it reaches the earth, this energy will spread Read more about Temperature of the Sun and Solar Constant[…]
Thermometry Thermometry is the science and practice of temperature measurement. Any measurable change in a thermometric probe can be used to mark temperature levels that should later be calibrated against an internationally agreed unit if the measure is to be related to other thermodynamic variables. An instrument is measure the temperature of a body is Read more about Thermometry[…]
Principles of Calorimetry Calorimetry is a scientific experimental measurement of the change of heat of a substance. A calorimeter is usually the container in which the heat change experiment is conducted. Calorimetry means “measuring heat”. When two bodies (one being solid and other being liquid or both being liquid) at different temperatures are mixed, heat Read more about Principles of Calorimetry[…]
Volume or Cubical Expansion When a solid is heated and its volume increases, then the expansion is called volume expansion (or) cubical expansion. Consider a rectangular parallel piped of slides l₁, l₂ and l₃. Its initial volume (V₀) = l₁ x l₂ x l₃. Differentiating both sides with respect to T, we get: . dV/ Read more about Volume or Cubical Expansion[…]
Superficial Expansion When the temperature of a two – dimensional object is changed, its area changes, then the expansion is called superficial expansion. A two – dimensional object, such as a thin metallic plate, changes area when its temperature is raised or lowered. For an isotope material the area expansion may be expressed in terms Read more about Superficial Expansion[…]
Thermal Expansion in Liquids Liquids do not have linear and superficial expansion but these only have volume expansion. Since liquids are always to be heated along with the vessel that contains them so initially on heating the system, the level of liquid in vessel falls but later on, it starts rising due to faster expansion Read more about Thermal Expansion in Liquids[…]
Current Density Current density is a point is defined as the amount of current flowing per unit area round that point provided area is normal to the direction of current. It is denoted by J. Current Density (J) = Current (I)/ Area (A). The unit of current of current density is A/ m². Current density Read more about Current Density[…]
Capacity of Parallel – Plate Capacitor with Dielectric When a dielectric material is placed between the plates of a capacitor, the capacitance of the capacitor increases.These are non-conductors up to a certain value of field depending upon their nature.If the field exceeds the limiting value, called dielectric strength, dielectric loses its insulating property and beings Read more about Capacity of Parallel – Plate Capacitor with Dielectric[…]
Dielectric Constant In many capacitors there is an insulating material such as paper or plastic between the plates. Such material, called a dielectric, can be used to maintain a physical separation of the plates.There are non – conductors up to a certain value of field depending upon theirnature. If the field exceeds the limiting value, Read more about Dielectric Constant[…]
Energy stored in a Charged Capacitor Work has to be done to transfer charges onto a conductor, against the force of repulsion from the already existing charges on it. This work is stored as a potential energy of the electric field of the conductor. Suppose a conductor of capacity C is to be charged up Read more about Energy stored in a Charged Capacitor[…]