List of top Physics Questions on Semiconductor Devices asked in MHT CET

In common emitter mode of a transistor, the current gain is 8. The input impedance is 25kΩ and load resistance is 75kΩ. The power gain is
A piece of semiconductor is connected in series in an electric circuit. On increasing the temperature, the current in the circuit will ______.
In a pure silicon crystal electron-hole concentration is $10^{16}$ per $\text{m}^3$ at $301\text{ K}$ . Now $10^{21}$ atoms of phosphorus are added per cubic metre. The new hole concentration in silicon is (in per $\text{m}^3$ )}
Diode and resistance are connected as shown. Which statement is TRUE?
In common emitter amplifier, a change of 0.2 mA in the base current causes a change of 5 mA in the collector current. If input resistance is 2 k$\Omega$ and voltage gain is 75, the load resistance used in the circuit is
What are the values of the currents flowing in each of the following diode circuits X and Y respectively? (Assume that the diodes are ideal)

Choose the correct answer from the options given below
A p-n junction photodiode is fabricated from a semiconductor with a band gap of $2.5\text{ eV}$. It can detect a signal of wavelength [Planck's constant = $6.6 \times 10^{-34}\text{ Js}$, $c = 3 \times 10^8\text{ m/s}$, $e = 1.6 \times 10^{-19}\text{ C}$]
For a transistor, $\frac{1}{\alpha_{DC}} - \frac{1}{\beta_{DC}}$ is equal to [$\alpha_{DC}$ and $\beta_{DC}$ are current amplification factors]
In a pure silicon, number of electrons and holes per unit volume are $1.6 \times 10^{16}\ \text{m}^{-3}$. If silicon is doped with Boron in a way that on doping hole density increases to $4 \times 10^{22}\ \text{m}^{-3}$. Then electron density in doped semiconductor will be
LED is manufactured using zinc selenide then it emits
Silicon and copper are cooled from 300 K to 100 K, the specific resistance (resistivity)
For a transistor, $\frac{1}{\alpha_{DC}} - \frac{1}{\beta_{DC}}$ is equal to [$\alpha_{DC}$ and $\beta_{DC}$ are current amplification factors]
In a pure silicon, number of electrons and holes per unit volume are $1.6 \times 10^{16}\ \text{m}^{-3}$. If silicon is doped with Boron in a way that on doping hole density increases to $4 \times 10^{22}\ \text{m}^{-3}$. Then electron density in doped semiconductor will be
Diode and resistance are connected as shown. Which statement is TRUE?