The ratio of number density of free electrons to holes for two different materials, A and B, are (i) equal to one and (ii) less than one respectively. Name the type of semiconductor to which A and B belong. Draw energy level diagram for A and B.

The ratio of number density of free electron and hole in p-type semiconductor is …….

Two numbers A and B are respectively 10% and 25% more than third number respectively. What is the ratio of A and B?

The ratio of angular momentum of electron in two successive orbit is a (a gt1) and their difference is b . Then a/b is equal to

The ratio of angular momentum of electron in two successive orbit is a (a gt1) and their difference is b . Then a/b is equal to

Using the microscopic form of Ohm's law (J=sigma E) , prove that conductivity of a metal can be written as sigma="ne"mu . Here n is the number of free electrons per unit volume and mu is mobility of free electrons . In case of semiconductors there are two types of conduction particles, one is free electrons and the other is known as a hole. Charge on the hole may be assumed to be equal and opposite of that on electron. The number density of free electrons and holes in the semiconducting material are n and p respectively. Assuming mu_e and mu_h as mobility of free electrons and holes respectively , write the exopression of conductivity of the semiconducting material.

Let n_(e) and n_(b) are the number density of electrons and holes in extrinsic semiconductor then-

The ratio of velocity,to speed of an object is __________ (i)one (ii)greater than one (iii)less than one (iv)either less than one or equal to one.

Which one of the following diagrams correctly represents the energy levels in the p-type semiconductor?