Semiconductor Electronics Questions

31 Practice QuestionsStart Practicing Now

[Medium]A light emitting diode is fabricated from a semiconductor whose energy band gap is 2.0 eV, and it emits photons whose energy equals this gap during re...
[Medium]On the forward characteristic of a junction diode, the current increases from 10 mA to 20 mA when the applied voltage rises from 0.70 V to 0.75 V. Wha...
[Medium]A silicon solar cell on a rooftop panel delivers electrical energy to a battery even though no external voltage source is connected across the cell it...
[Medium]A centre-tapped full-wave rectifier is supplied from a transformer connected to a 50 Hz line, and it conducts during both halves of every input cycle....
[Easy]A single diode half-wave rectifier is driven by an alternating mains supply whose frequency is 50 Hz. What is the fundamental frequency of the pulsati...
[Medium]A junction diode is connected so that its n-side is held at a higher potential than its p-side by an external battery of moderate voltage. Which descr...
[Medium]As a block of pure semiconductor is gradually warmed from room temperature, its measured electrical resistance is observed to fall steadily. Which sta...
[Medium]An unregulated 10 V source is connected through a 100 ohm series resistor to a 5 V Zener diode operating in breakdown, with no load resistor attached ...
[Medium]A silicon diode with a constant forward voltage drop of 0.7 V is connected in series with a resistor across a 5 V battery, and the resistor is chosen ...
[Easy]A photodiode used as a light sensor in an automatic street lamp is deliberately connected in reverse bias rather than forward bias during normal opera...
[Medium]A silicon crystal with intrinsic carrier concentration \(1.5 \times 10^{16}\,\text{m}^{-3}\) is doped so that its free electron density rises to \(4.5...
[Easy]A materials technician measures the forbidden energy gap of an unknown crystalline solid and finds it to be close to 1.1 eV at ordinary room temperatu...
[Easy]Immediately after a p-n junction is formed and left without any external battery, a thin region near the boundary becomes free of mobile carriers. Whi...
[Easy]A silicon wafer is uniformly doped with a trace of pentavalent arsenic to raise its conductivity for a temperature sensor. Which mobile charge carrier...
[Easy]In a perfectly pure silicon crystal kept at room temperature, thermal vibrations alone create mobile charge carriers without any added impurity. How d...
[Hard]High-frequency performance of transistor limited mainly by:...
[Hard]Simplify A + A B (Boolean). Result is:...
[Hard]LED emits light when electrons recombine with holes releasing energy equal to:...
[Hard]Solar cell differs from photodiode mainly because it:...
[Medium]Photodiode operated under reverse bias generates current proportional to:...
[Medium]A full-wave rectifier converts AC into:...
[Easy]Output of AND gate is 1 only when:...
[Hard]In an n-p-n transistor, large collector current flows because:...
[Hard]Zener breakdown in heavily doped diode is due to:...
[Medium]Reverse bias causes current to be:...
[Medium]Forward bias reduces barrier allowing:...
[Medium]Depletion region forms due to:...
[Easy]In intrinsic semiconductor Fermi level lies approximately:...
[Easy]Adding pentavalent impurity to silicon creates:...
[Easy]Intrinsic semiconductor conductivity primarily depends on:...
[Medium]The logic gate shown in the figure represents:...