Aplanatic points.
A Spherical lens, which is free from the defects of spherical aberration and coma is called an aplanatic lens. A pair of conjugate points free from spherical aberration and coma is called aplanatic points.
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What is Freundlich adsorption isotherm ?
Explanation:- The variation in the amount of gas adsorbed by the adsorbent with pressure at constant temperature can be expressed by means of a curve termed as adsorption isotherm. According to freundlich isotherm, The extent of adsorption of a gas per unit mass of adsorbent depends upon the pressure of that gas. I.e Look at the Graph,(x/m) vs (p) Equation (1) is the general form of freundlich adsorption isotherm. Case-1( at low pressure) If x/m =kp¹ That implies 1/n=1 I.e n=1 So at low pressure freundlich adsorption isotherm holds good because initially their is more adsorption occur. Case-2 (at high pressure) If x/m=constant i.e1/n=0 That implies n=infinity So at high pressure x/m independent on pressure because after saturation pressure their is no adsorption occur due to no space on adsorbent. At saturation pressure Amount of gas adsorbed=amount of gas desorbed. Look at the logarithm graph of equation (1) This is al...
polaroids.
It is a device which is used to produce the plane polarised light. It is based on the principle of selective absorption and more effective than the tourmaline crystal. Polaroid allows the light oscillations parallel to the transmission axis to pass through them. The crystal or polaroid on which the unpolarised light is incident is called polariser. Crystal or polaroid on which polarised light is incident is called analyser.
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