Electrical Engineering Material Question Bank solution pdf IOE All Subject Note pdf

 

IOE Electrical Engineering Material OLD Question solutions of IOE Regular and Back Questions with short theory important numerical as well as derivations are included here . Strictly in this page you can read electrical engineering notes for 3rd semester as pulchowk campus engineering notes . Here you will find ioe old question answers that are asked in ioe final examination of electrical engineering material according to ioe syllabus for electrical engineering material (EE502) 

IOE ALL SUBJECT NOTES

Chapter 1 : Theory of Metal

Define population density

If we multiply density of state Z(E) & probability of occupation index F(E) then we obtain the number of electrons (per unit energy) per unit volume which is denoted by nE & is called population density.

OR

( If we multiply density of states Z(E) and probability of occupation F(E) then we will get number of electrons occupied in a state i.e. nE and is called population density.)

 Thermionic Emission

When a metal is heated the electron within it becomes highly energetic and gets ejected from its surface . This process of ejection of electron from metal surface at high temperature is called as thermionic  emission.

Work function

There is a minimum (threshold) value of energy that the electron must posses if it is to leave the metal surface. This threshold value of energy is called work function of the metal(ɸ).

Schottky Effect

When an electric field applied to a metal is increased, the work function is decreased and hence thermionic emission from the metal surface increases. This effect is called Schottky effect.

Explain the necessity of quantum mechanics.

1. To understand the tunneling phenomena.
2. To understand the photoelectric effect.
3. To understand the behavior or nature of microscopic particles or electrons.

Chapter 2 : Free Electron Theory of Conduction in Metal

Crystalline Structure: 

It is an periodic arrangement of atoms( or molecules) in a regular pattern in space. It is the combination of lattice and basis where lattice is the infinite periodic arrangement of points in space and basis is the pair of atoms or molecules when these basis occupy the points of a lattice then we get a crystal structure.

Unit cell: 

It is the simplest structure obtained from the crystal structure. When we extend the unit cell structure in all directions in space then we get a crystal structure.

Co-ordination Number : 

It is the number of nearest neighboring atoms or the number of atoms touching the largest atom of a unit cell.

Packing density: 

It is the ratio of volume occupied by atoms to the volume of unit cell. It signifies how densely the atoms are packed in the unit cell.

Latice parameter : a, α ,β ,𝛄

IOE 2074 Ashwin Electrical Engineering Material Old Question Solution

1.a). Explain the importance of quantum mechanics. Differentiate between classical and quantum mechanics with suitable examples.

Ans: The importance of quantum mechanics are listed below:-

• To understand the tunneling phenomena.
• To understand the photoelectric effect.
• To understand the nature of microscopic particles.
• Quantum mechanics is a generalized form of mechanics which is applicable to very small object like electrons in the atom.
• All the electronic phenomena within the materials can not be explained with the help of the classical mechanics rather explained by quantum mechanics.

Difference between  classical and quantum mechanics are given below :- 

Classical Mechanics

1. It can be applied to macroscopic bodies.
2. It is based on Newton's law of motion.
3. The state of a system is defined by specifying all the forces acting on the particles as well as their position and velocity. The future state then can be predicted with certainty.
4. It is based on Maxwell's electromagnetic wave theory. 

Quantum Mechanics

1. It can be applied to microscopic bodies.
2. It follow Heisenberg Uncertainty principal.
3. It gives the probability of finding the particles at various location in space.
4. It is based on plank's quantum theory.

IOE 2068 Shrawan Electrical Engineering Material Past question solution

1.a) What is tunneling phenomenon? Derive the expression for the probability of tunneling the potential barrier of width L and height V by electron.

Ans: Tunneling phenomenon: Tunneling is a quantum mechanical phenomena such that an electron or wave can penetrate a potential barrier and appear at another region. This is possible only if the potential barrier is relatively lower and width of potential barrier is relatively narrower. 

Fermi Energy: 

In metal fermi energy is defined as the energy of highest filled energy level at temperature of absolute zero .