If ${\mathrm{n}}_{\mathrm{e}}$ and ${\mathrm{v}}_{\mathrm{d}}$ be the number of electrons and drift velocity in a semiconductor. When the temperature is increased

(1) ${\mathrm{n}}_{\mathrm{e}}$ increases and ${\mathrm{v}}_{\mathrm{d}}$ decreases

(2) ${\mathrm{n}}_{\mathrm{e}}$ decreases and ${\mathrm{v}}_{\mathrm{d}}$ increases

(3) Both ${\mathrm{n}}_{\mathrm{e}}$ and ${\mathrm{v}}_{\mathrm{d}}$ increases

(4) Both ${\mathrm{n}}_{\mathrm{e}}$ and ${\mathrm{v}}_{\mathrm{d}}$ decreases

The energy gap of silicon is 1.14 eV. The maximum wavelength at which silicon will begin absorbing energy is

(1) 10888 Å                   

(2) 1088.8 Å

(3) 108.88 Å                   

(4) 10.888 Å

Which of the following energy band diagram shows the N-type semiconductor

1. 

2. 

3. 

4. 

The mobility of free electrons is greater than that of free holes because

1. They carry negative charge

2. They are light

3. They mutually collide less

4. They require low energy to continue their motion

The electron mobility in N-type germanium is 3900 ${\mathrm{cm}}^2$/v-s and its conductivity is 6.24 mho/cm, then impurity concentration will be if the effect of cotters is negligible
(a) ${10}^{15} /{\mathrm{cm}}^3$                  (b) ${10}^{13}/{\mathrm{cm}}^3$
(c) ${10}^{12}/{\mathrm{cm}}^3$                   (d) ${10}^{16}/{\mathrm{cm}}^3$

Which of the energy band diagrams shown in the figure corresponds to that of a semiconductor

1. 

2. 

3. 

4. 

The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that

(1) Sample X is undoped while samples Y and Z have been doped with a third group and a fifth group impurity respectively

(2) Sample X is undoped while both samples Y and Z have been doped with a fifth group impurity

(3) Sample X has been doped with equal amounts of third and fifth group impurities while samples Y and Z are undoped

(4) Sample X is undoped while samples Y and Z have been doped with a fifth group and a third group impurity respectively

In a semiconducting material, the mobilities of electrons and holes are \(\mu_e\) and \(\mu_{h}\) respectively. Which of the following is true?
1. \(\mu_{e} > \mu _{h}\)
2. \(\mu_{e} < \mu _{h}\)
3. \(\mu_{e} = \mu _{h}\)
4. \(\mu_{e} <0; ~\mu _{h}>0\)

The temperature (T) dependence of resistivity ($\rho$) of a semiconductor is represented by

1. 

2. 

3. 

4. 

In a forward biased P-N junction diode, the potential barrier in the depletion region is of the form

1. 

2. 

3. 

4.