Pure Si at 500 K has equal number of electron (nₑ) and hole (nₕ) concentrations

⇦

⇨

Pure Si at 500 K has equal number of electron (nₑ) and hole (nₕ) concentrations of 1.5 x 10¹⁶ m⁻³. Doping by indium increases nₕ to 4.5 x 10²² m⁻³. The doped semiconductor is of

Options

(a) n-type with electron concentration nₑ = 5 x 10²² m⁻³
(b) p-type with electron concentration nₑ = 2.5 x 10¹⁰ m⁻³
(c) n-type with electron concentration nₑ = 2.5 x 10²³ m⁻³
(d) p-type with electron concentration nₑ = 5 x 10⁹ m⁻³

Correct Answer:

p-type with electron concentration nₑ = 5 x 10⁹ m⁻³

Explanation:

nᵢ² = nₑ nₕ
(1.5 x 10¹⁶)² = nₑ (4.5 x 10²²)
⇒ nₑ = 0.5 x 10¹⁰ or nₑ = 5 x 10⁹
Given nₕ = 4.5 x 10²² ⇒ nₕ >> nₑ
semiconductor is p-type and
nₑ = 5 x 10⁹ m⁻³.

Related Questions:

1. A boat which has a speed of 5 kmh⁻¹ in still water crosses river of width 1 km long
2. The moment of inertia of a uniform circular disc of radius R and mass M about an axis
3. Shearing stress causes change in
4. If by mistake voltmeter is connected in series and ammeter in parallel then
5. Two coils of self inductance 2 mH and 8 mH are placed so close together

Topics: Electronic Devices (124)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends