What is space charge ?

-
Answer:-
If the plate of the vacuum tube is not given a positive potential, electrons emitted by the filament get collected around it to form a cloud of negative charge.This is called space charge.If not removed it will stop thermonic emission.

Comments

Post a Comment

Popular posts from this blog

What is Freundlich adsorption isotherm ?

-
Image
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 all about freundlich adsor
Read more

Difference between molecularity & order of reaction

-
Answer:-                                      order of Molecularity                                reaction       Common points:- • It's value does not         •Its value also  exceed three.                      does not exceed                                              three. • Depends upon the          •It also depends  Condition of a react           upon the conidti ion.                                       on of a reaction.  Difference points:- • It is always a whole         • It may be posit number,non-zero,non-      ive or negative in negative.                              teger, zero, frac-                                                tion. • It can be obtained            • It can obtai- from a simple balanced       ned only         chemical reaction.                 experimental-                                                  y.                                                   
Read more