Semiconductor Diode MCQ Level – 1 - Physics MCQ

Correct Answer :- C

Explanation : It generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. The energy band gaps of silicon and germanium are 1.1eV and 0.

The band gap of GaAs results in efficient emission of infrared light at 1.424 eV.

Explanation: In order to use a transistor as an amplifier the emitter-base junction is set up as forward biased and the base-collector junction is set up as reverse biased. This is the criteria for making a transistor function as an amplifier.

A Zener diode is used to get constant DC voltage from a DC unregulated output of a rectifier.

Therefore, the correct answer is A.

When the voltage is −5 V, the diode will be reverse biased and the voltage drop across the resistor will be zero as there is no current in the circuit. And when voltage is +5 V, the diode will be forward biased, the voltage drop across resistor will be thAe same as input voltage.

When an element of fifth group is doped in pure germanium/silicon due to excess of an electron, the semiconductor is known as n-type semiconductor. In n-type semiconductor, majority of carrier is electron. If the element of third group is added, the semiconductor is known as p-type. In this case, majority of carriers is hole.
The correct answer is: boron and aluminium

Emax = -2(V_bi + V_R) / W
= -2(2 + 5) / (7 * 10^-2)
= -200V/m.

According to Fermi-Dirac distribution law, the probability of an electron in finding energy level E at temperature T is given as



By (i) and (ii),

The correct answer is: half

The depletion layer in p-n junction consists of the layer of positively charged donors on the n-side and negatively charged acceptors on p-side.

The correct answer is: Positively charged donors on the n-side and negatively charged acceptors on the p-side

Under thermal equilibrium, the product of free electron concentration n and hole 9 e concentration n_h is constant equal to  where n_i is the concentration of intrinsic semiconductor

The correct answer is: