Physical quantities that semiconductors can sense A semiconductor device can be engineered to detect which of the following types of stimuli?

Introduction / Context:
Semiconductors enable sensors that convert physical phenomena into electrical signals. Through material choice, device geometry, and doping profiles, they can sense magnetic fields, temperature, pressure, light, chemicals, and more.

Given Data / Assumptions:

• Hall-effect devices for magnetic fields.
• Thermistors and diode junctions for temperature.
• Piezoresistive elements and MEMS structures for pressure.

Concept / Approach:
Key transduction mechanisms include: Hall effect (voltage orthogonal to current and magnetic field), temperature-dependent carrier statistics and bandgap leading to resistance or junction-voltage changes, and piezoresistivity where strain alters band structure and mobility, changing resistance.

Step-by-Step Solution:
Magnetism: employ Hall plates; output voltage ∝ current * magnetic flux density.Temperature: use thermistors (NTC/PTC) or diode V_f versus temperature (~−2 mV/°C for silicon).Pressure: build piezoresistors on diaphragms; pressure causes strain → resistance change.Hence, semiconductors can sense all listed stimuli.

Verification / Alternative check:
Automotive and consumer electronics utilize all three: wheel-speed Hall sensors, on-die thermal sensors, and MEMS barometers.

Why Other Options Are Wrong:
Magnetism/Temperature/Pressure alone: each is true, but the most complete answer is that semiconductor technology covers all.

Common Pitfalls:
Assuming only optical sensing; in reality, semiconductor physics enables multi-domain sensing.

Final Answer:
all of the above