Determine the number of density of donor atoms which have to be added to an intrinsic germanium semiconductor to produce an N-type semi-conductor of conductivity 6.4 `Omega cm^(-1)` . Given that mobility of electron in N-type Ge is 4000 `cm^(2)//Vs`. Neglect the contribution of holes. to conductivity.

The amount of energy released when an electron is added to an isolated gaseous atom to produce a monovalent anion is called electron affinity or first electron affinity or electron gain enthalpy. The first electron is given a negative sign as the addition of an electron to a neutral atom is an exoergic process. The addition of electron to A^(-1) requires energy to overcome the force of repulsion. Thus, the second electron affinity is an endoergic process. The magnitude of electron affinity depends on a number of factors such as (i) atomic size (ii) effective nuclear charge (iii) screening effect (iv) half and fully filled orbitals and (v) shape of orbital. In general, electron affinity increases as the atomic radii decrease in a period. However, there are exceptions when the atoms have stable configurations. In a group, electron affinity decreases as the size increases. However, the members of 3rd period have somewhat higher values than the members in the 2nd period of the same subgroups. Which of the following processes is endoergic in nature ?

The amount of energy released when an electron is added to an isolated gaseous atom to produce a monovalent anion is called electron affinity or first electron affinity or electron gain enthalpy. The first electron is given a negative sign as the addition of an electron to a neutral atom is an exoergic process. The addition of electron to A^(-1) requires energy to overcome the force of repulsion. Thus, the second electron affinity is an endoergic process. The magnitude of electron affinity depends on a number of factors such as (i) atomic size (ii) effective nuclear charge (iii) screening effect (iv) half and fully filled orbitals and (v) shape of orbital. In general, electron affinity increases as the atomic radii decrease in a period. However, there are exceptions when the atoms have stable configurations. In a group, electron affinity decreases as the size increases. However, the members of 3rd period have somewhat higher values than the members in the 2nd period of the same subgroups. Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species ?

The amount of energy released when an electron is added to an isolated gaseous atom to produce a monovalent anion is called electron affinity or first electron affinity or electron gain enthalpy. The first electron is given a negative sign as the addition of an electron to a neutral atom is an exoergic process. The addition of electron to A^(-1) requires energy to overcome the force of repulsion. Thus, the second electron affinity is an endoergic process. The magnitude of electron affinity depends on a number of factors such as (i) atomic size (ii) effective nuclear charge (iii) screening effect (iv) half and fully filled orbitals and (v) shape of orbital. In general, electron affinity increases as the atomic radii decrease in a period. However, there are exceptions when the atoms have stable configurations. In a group, electron affinity decreases as the size increases. However, the members of 3rd period have somewhat higher values than the members in the 2nd period of the same subgroups. Which of the following species has the highest electron affinity?

Find the number density of impurity atoms that must be added to a pure silicon crystal inorder to convert it to have resistivity (i) 10^(-1) Omega m n-type silicon (ii) 10^(-1) Omega m p-type silicon. Give for silicon: mu_(e) =0.135 m^(2)V^(-1)s^(-1) and mu_(h) =0.048 m^(2)V^(-1)s^(-1) .

In a pure semiconductor, the number of conduction electrons is 6xx10^(19) per cubic metre. How many holes are there in a sample of size 1 cm xx cm xx 2 mm ?

Conductors allow the passage of electric current through them. Metallic and electrolytic are the two types of conductors. Current carriers in metallic and electrolytic conductors are free electrons and free ions respectively. Specific conductance or conductivity of the electrolyte solution is given by the following relation: K= cx (l)/(A) where, c=1/R is the conductance and 1/A is the cell constant, Molar conductance (^^_m) and equivalence conductance (^^_e) of an electrolyte solution are calculated using the following similar relations: ^^_m = K xx (1000)/(M) ^^_(e) = K xx (1000)/(N) where, M and N are the molarity and normality of the solution respectively. Molar conductance of strong electrolyte depends on concentration : ^^_m = ^^_m^(0) - b sqrt(C) ^^_m^(0) = molar conductance at infinite dilution C = concentration of the solution b = constant The degrees of dissociation of weak electrolytes are calculated as alpha = (^^_m)/(^^_m^(0)) = (^^_e)/(^^_e^(0)) Which of the following decreases on dilution of electrolytic solution?

Conductors allow the passage of electric current through them. Metallic and electrolytic are the two types of conductors. Current carriers in metallic and electrolytic conductors are free electrons and free ions respectively. Specific conductance or conductivity of the electrolyte solution is given by the following relation: K= cx (l)/(A) where, c=1/R is the conductance and 1/A is the cell constant, Molar conductance (^^_m) and equivalence conductance (^^_e) of an electrolyte solution are calculated using the following similar relations: ^^_m = K xx (1000)/(M) ^^_(e) = K xx (1000)/(N) where, M and N are the molarity and normality of the solution respectively. Molar conductance of strong electrolyte depends on concentration : ^^_m = ^^_m^(0) - b sqrt(C) ^^_m^(0) = molar conductance at infinite dilution C = concentration of the solution b = constant The degrees of dissociation of weak electrolytes are calculated as alpha = (^^_m)/(^^_m^(0)) = (^^_e)/(^^_e^(0)) Which of the following equality holds good for the strong electrolytes?

Conductors allow the passage of electric current through them. Metallic and electrolytic are the two types of conductors. Current carriers in metallic and electrolytic conductors are free electrons and free ions respectively. Specific conductance or conductivity of the electrolyte solution is given by the following relation: K= cx (l)/(A) where, c=1/R is the conductance and 1/A is the cell constant, Molar conductance (^^_m) and equivalence conductance (^^_e) of an electrolyte solution are calculated using the following similar relations: ^^_m = K xx (1000)/(M) ^^_(e) = K xx (1000)/(N) where, M and N are the molarity and normality of the solution respectively. Molar conductance of strong electrolyte depends on concentration : ^^_m = ^^_m^(0) - b sqrt(C) ^^_m^(0) = molar conductance at infinite dilution C = concentration of the solution b = constant The degrees of dissociation of weak electrolytes are calculated as alpha = (^^_m)/(^^_m^(0)) = (^^_e)/(^^_e^(0)) For which of the following electrolytic solution ^^_m and ^^_e are equal ?