Electron Devices : Surprise Quiz -2

In a Tunnel Diode, what causes the negative resistance region in its I-V characteristics?

• Recombination of minority carriers

• Avalanche breakdown

• Quantum tunneling through a narrow depletion layer

• High injection level of majority carriers

A Unijunction Transistor (UJT) is used in a triggering circuit. Which of the following characteristics is critical for its operation?

• Peak inverse voltage

• Valley point voltage

• Early voltage

• Saturation current

Why are Avalanche Photodiodes preferred in optical communication receivers over PIN diodes?

• Lower response time

• Higher noise margin

• Internal gain due to impact ionization

• Simpler biasing requirements

In a MESFET, the metal-semiconductor junction acts as:

• A forward-biased base

• A rectifier

• A conducting channel

• A reverse-biased gate

What advantage do TFETs (Tunnel Field-Effect Transistors) offer over conventional MOSFETs in low-power digital circuits?

• Higher threshold voltage

• Larger gate capacitance

• Steeper subthreshold slope

• Higher drive current

HEMTs (High Electron Mobility Transistors) are typically made using which materials to achieve high electron mobility?

• Silicon and silicon dioxide

• GaAs and AlGaAs

• Germanium and polysilicon

• Indium and tin oxide

In a varactor diode, how does the capacitance vary with reverse bias voltage?

• Increases linearly

• Decreases exponentially

• Remains constant

• Inversely with the square root of voltage

Silicon Nanowire Transistors are considered for future scaling due to:

• Their ability to emit light

• 3D gate control improving electrostatics

• Reduced channel mobility

• Use of polycrystalline silicon channels

What is the primary role of CCDs (Charge-Coupled Devices) in imaging?

• Convert light photons into electrons and transfer charges

• Amplify incoming light signals

• Modulate light intensity

• Reflect infrared radiation

In an opto-coupler, the electrical isolation between input and output is achieved by:

• A transformer

• An inductor

• A light-emitting and light-detecting pair

• A Schottky barrier