NEET Practice Questions (MCQs) with Answers & Solutions

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

Use of transistor as an amplifier works in the region -

Which of the following is correct for n-type semiconductor?

$$\begin{gathered} \mathrm{If} \mathrm{\alpha } \mathrm{be} \mathrm{the} \mathrm{current} \mathrm{gain} \mathrm{of} \mathrm{a} \mathrm{transistor} \mathrm{in} \mathrm{common} \mathrm{base} \mathrm{mode} \mathrm{and} \mathrm{\beta } \mathrm{be} \mathrm{the} \mathrm{current} \mathrm{gain} \mathrm{in} \\ \mathrm{common} \mathrm{emitter} \mathrm{mode} \mathrm{then}- \end{gathered}$$

For a transistor amplifier, the power gain and voltage gain are 150 and 10 respectively. The current gain is-

In semiconductors, which of the following gives the law of mass action (where symbols have their usual meanings)-

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 m and Mobility of holes is ${\mathrm{m}}_{\mathrm{h}},$ will be

A transistor is used in common emitter mode in an amplifier circuit. When a signal of 10 mV is added to the base-emitter voltage, the base current changes by 15 $\mu$A and the collector current changes by 1.5 mA. The current gain b will be

In a common-emitter transistor, the phase difference between input and output is:

$$\begin{gathered} \mathrm{A} \mathrm{semiconductor} \mathrm{is} \mathrm{known} \mathrm{to} \mathrm{have} \mathrm{an} \mathrm{electron} \mathrm{concentration} \mathrm{of} 8 \mathrm{x} {10}^{13} {\mathrm{cm}}^{-3} \mathrm{and} \mathrm{hole} \mathrm{concentration} \mathrm{of} 5 \mathrm{x} {10}^{12} {\mathrm{cm}}^{-3}. \\ \mathrm{The} \mathrm{semiconductor} \mathrm{is} \end{gathered}$$