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what is internal energy ?

Every system is made of atoms, ions or molecules. Energy is stored in atoms,ions and molecules in different forms as electronic energy, nuclear energy, potential energy, kinetic energy etc. “The total energy stored in a system under a given set of conditions is called it's internal energy or intrinsic energy, U”.

Bond enthalpy.

Bond energy or enthalpy of a given bond is defined as the average of energies required to dissociate one mole of said bond present in different gaseous compounds into free atoms or radicals in the gaseous state. The word 'average' in the definition of bond energy is used because the bond energy of a particular bond is not the same when present in different compounds. Therefore, an average value is taken. For example, the O—H bond energy in water molecule is the average of the two bond dissociation energies.

Bandwidth.

It is defined as the range of frequency over which the voltage gain is equal to or greater than 1/√2 of mid frequency voltage gain.   

RMS value of current.

Root mean square (RMS) value of current is that value of steady current which produces same heating effect through load resistance in same time as is produce by AC in one of its cycle.

forward current transfer ratio.

Forward current transfer ratio (α) for common base operation is defined as the ratio between change in collector current to the change in emitter current keeping collector base voltage constant.

Non inverting amplifier.

In non inverting amplifier the input signal voltage is applied to the non inverting input terminal of op-amp & inverting terminal is grounded. A part of output signal voltage is fedback to the inverting input terminal of op-amp through fedback resistance.

Inverting amplifier.

In inverting amplifier the input signal voltage is applied to the inverting input terminal of op-amp & the non-inverting input terminal is grounded.