ni2=nenhne=nh(ni)2ne=(4.5×1022)(1.5×1016)2ne=5×109 m−3 So, nf1≫ne semiconductor is p-type.
Pure Si at 500 ~K has equal number of electron (n_e ) and hole (n_h ) concentrations of 1.5 × 10^16 ~m^-3. Doping by indium increases n_h to 4.5 ×…
NEET UG 2011 — Physics Modern Physics
2011mcqeasy
Pure Si at 500 K has equal number of electron (ne) and hole (nh) concentrations of 1.5×1016 m−3. Doping by indium increases nh to 4.5×1022 m−3. The doped semiconductor is of
Official previous-year question
Held on 30 Apr 2011 · Verified 9 Jul 2026.
Options
- A
n-type with electron concentration ne=5×1022 m−3
- B
p-type with electron concentration ne=2.5×1010 m−3
- C
n-type with electron concentration ne=2.5×1023 m−3
- D
p-type having electron concentration ne=5×109 m−3
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
NEET UG Modern Physics in other years
More NEET UG Modern Physics questions
A photon and an electron (mass $m$ ) have the same energy $E$. The ratio ( $\lambda_{\text {photon }} / \lambda_{\text {electron }}$ ) of their de Broglie wavelengths is: (c is the speed of light)
2025medium
The output $(\mathrm{Y})$ of the given logic implementation is similar to the output of an/a _____ gate. 
2025medium
The maximum kinetic energy of photoelectrons from a surface with work function φ = 2 eV when light of λ = 4000 Å falls on it is (hc = 12400 eV·Å):
2025easy
A full wave rectifier circuit with diodes $\left(D_1\right)$ and $\left(D_2\right)$ is shown in the figure. If input supply voltage $V_{\text {in }}=220 \sin (100 \pi t)$ volt, then at $t=15 \mathrm{msec}$ 
2025medium
A particle of mass $m$ is moving around the origin with a constant force $F$ pulling it towards the origin. If Bohr model is used to describe its motion, the radius $r$ of the $n^{\text {th }}$ orbit and the particle's speed $v$ in the orbit depend on $n$ as
2025medium
Other Physics topics for NEET UG
Keep practicing Modern Physics
Work through every NEET UG Modern Physics PYQ, year by year.