The conductivity of an n-type semiconductor whose density of conduction electrons is ${\mathrm{n}}_{\mathrm{e}}$, Density of holes is ${\mathrm{n}}_{\mathrm{h}}$, Mobility of conduction electrons is ${\mathrm{m}}_{\mathrm{e}}$and Mobility of holes is ${\mathrm{m}}_{\mathrm{h}},$ will be

1.  $\mathrm{e}\left[{\mathrm{n}}_{\mathrm{e}}{\mathrm{m}}_{\mathrm{h}}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{n}}_{\mathrm{e}}{\mathrm{m}}_{\mathrm{e}}\right]<mspace\; width="1em"></mspace>$

2.  $\mathrm{e}\left[{\mathrm{n}}_{\mathrm{e}}{\mathrm{m}}_{\mathrm{e}}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{n}}_{\mathrm{h}}{\mathrm{m}}_{\mathrm{e}}\right]<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

3.  ${\mathrm{en}}_{\mathrm{e}}\left[{\mathrm{m}}_{\mathrm{e}}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{m}}_{\mathrm{h}}\right]<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

4.  $\mathrm{e}\left[{\mathrm{n}}_{\mathrm{e}}{\mathrm{m}}_{\mathrm{e}}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{n}}_{\mathrm{h}}{\mathrm{m}}_{\mathrm{h}}\right]<mspace\; width="1em"></mspace>$

The current through an ideal p-n junction diode shown in the circuit will be:

1.  5 A
2.  0.2 A 
3.  0.6 A
4.  zero

$\mathrm{In}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{given}<mspace\; width="1em"></mspace>\mathrm{circuit}<mspace\; width="1em"></mspace>\mathrm{power}<mspace\; width="1em"></mspace>$
$\mathrm{developed}<mspace\; width="1em"></mspace>\mathrm{in}<mspace\; width="1em"></mspace>1\mathrm{k\Omega }<mspace\; width="1em"></mspace>\mathrm{resistor}<mspace\; width="1em"></mspace>\mathrm{is}$

      ​​​​​​​

1.  36 mW

2.  12 mW

3.  144 mW

4.  64 mW

A semiconductor is known to have an electron concentration of \(8\times 10^{13}~\text{cm}^{-3},\) and a hole concentration of \(5\times 10^{2}~\text{cm}^{-3}.\) The semiconductor is:

In the given figure, the potential difference between \(A\) and \(B\) is:

$\mathrm{If}<mspace\; width="1em"></mspace>\mathrm{\alpha }<mspace\; width="1em"></mspace>\mathrm{be}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{current}<mspace\; width="1em"></mspace>\mathrm{gain}<mspace\; width="1em"></mspace>\mathrm{of}<mspace\; width="1em"></mspace>\mathrm{a}<mspace\; width="1em"></mspace>\mathrm{transistor}<mspace\; width="1em"></mspace>\mathrm{in}<mspace\; width="1em"></mspace>\mathrm{common}<mspace\; width="1em"></mspace>\mathrm{base}<mspace\; width="1em"></mspace>\mathrm{mode}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>\mathrm{\beta }<mspace\; width="1em"></mspace>\mathrm{be}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{current}<mspace\; width="1em"></mspace>\mathrm{gain}<mspace\; width="1em"></mspace>\mathrm{in}$
$\mathrm{common}<mspace\; width="1em"></mspace>\mathrm{emitter}<mspace\; width="1em"></mspace>\mathrm{mode}<mspace\; width="1em"></mspace>\mathrm{then}-$

1.  $\mathrm{\alpha }<mspace\; width="1em"></mspace><<mspace\; width="1em"></mspace>1<mspace\; width="1em"></mspace>$

2.  $\mathrm{\beta }<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>1<mspace\; width="1em"></mspace>$

3.  $\mathrm{\alpha }<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>\frac{\mathrm{\beta }}{1<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>\mathrm{\beta }}$

4.  All of these

Which of the following is correct for \(\mathrm{n}\)-type semiconductors?

When a transistor is used as a switch it is in:

1.  Active state

2.  Cut off state

3.  Saturation state

4.  Both cut off state and saturation state are possible