Semiconductor Electronics: Materials, Devices and

In a semiconductor, the number density of intrinsic charge carriers at 27°C is 1.5 * 10¹? / m³. If the semiconductor is doped with impurity atom, the hole density increases to 4.5*10²² / m³. The electron density in the doped semiconductor is __________ x 10? / m³.

A transistor is connected in common emitter circuit configuration, then collector supply voltage is 10 V and the voltage drop across a resistor of 1000Ω in the collector is 0.6 V. If the current gain factor (β) is 24, then the base current is _______ µA. (Round off to the Nearest Integer)

The zener diode has a V_z = 30V. The current passing through the diode for the following circuit is…………mA.

Draw the output signal Y in the given combination of gates.

The circuit contains two diodes each with a forward resistance of 50 $\Omega$ and with infinite reverse resistance. If the battery voltage is 6 V, the current through the 120 $\Omega$ resistance is---------mA.

LED is constructed from Ga – As – P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour.

[h = 6.63 * 10^-34 Js and c = 3 * 10⁸ ms^-1]

Given below are two statements:

Statement I :  PN junction diodes can be used to function as transistor simply by connecting two diodes, back to back, which acts as the base terminal.

Statement II : In the study of transistor, the amplification factor b indicates ratio of the collector current to the base current.

In the light of the above statements, choose the correct answer from the options given below.

Zener breakdown occurs in a P- n junction having P and n both:

A 5 V battery is connected across the points X and Y. Assume D₁ and D₂ to the normal silicon diodes. Find the current supplies by the battery if the +ve terminal of the battery is connected to point X.