Zener diode is used for:-

1.  Rectification

2.  Stabilisation

3.  Amplification

4.  Producing oscillations in an oscillator

A semiconductor is known to have an electron concentration of $8\times {10}^{13} per c{m}^2$ and hole concentration $5\times {10}^{12} per c{m}^3$. The semiconductor is

1.  n type

2.  p type

3.  Intrinsic 

4.  None of these 

A Ge specimen is doped with Al. The concentration of acceptor atoms is $={10}^{21} \mathrm{atoms}/{\mathrm{m}}^3$. Given that the intrinsic concentration of electrons in the specimen is ${10}^{19}/m^3$. The new electron concentration is

1.  ${10}^{17}/m^3$

2.  ${10}^{15}/m^3$

3.  ${10}^4/m^3$

4.  ${10}^2/m^3$

How many NAND gates are used to form AND gate?

1.  1

2.  2

3.  3

4.  4

In the half-wave rectifier circuit shown. Which one of the following wave forms is true for ${\mathrm{V}}_{\mathrm{CD}}$, the output across C and D?

1. 

2. 

3. 

4. 

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

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

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

Let ${\mathrm{n}}_{\mathrm{P}}$ and ${\mathrm{n}}_{\mathrm{e}}$ be the number of holes and conduction electrons respectively in a semiconductor. Then

(1) ${\mathrm{n}}_{\mathrm{P}}$>${\mathrm{n}}_{\mathrm{e}}$ in an intrinsic semiconductor

(2) ${\mathrm{n}}_{\mathrm{P}}$=${\mathrm{n}}_{\mathrm{e}}$ in an extrinsic semiconductor

(3) ${\mathrm{n}}_{\mathrm{P}}$=${\mathrm{n}}_{\mathrm{e}}$ in an intrinsic semiconductor

(4) ${\mathrm{n}}_{\mathrm{e}}$<${\mathrm{n}}_{\mathrm{P}}$ in an intrinsic semiconductor

Which of the following logic gate is a universal gate?
1. OR
2. NOT
3. AND
4. NOR