1
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
Pure Si at 500 K has equal number of electron (ne) and hole (nh) concentrations of 1.5 $$ \times $$ 1016 m$$-$$3. Doping by indium increases nh to 4.5 $$ \times $$ 1022 m$$-$$3. The doped semiconductor is of
A
p-type having electron concentration ne = 5 $$ \times $$ 109 m$$-$$3
B
n-type with electron concentration ne = 5 $$ \times $$ 1022 m$$-$$3
C
p-type with electron concentration ne = 2.5 $$ \times $$ 1010 m$$-$$3
D
n-type with electron concentration ne = 2.5 $$ \times $$ 1023 m$$-$$3
2
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
In the following figure, the diodes which are forward biased, are

AIPMT 2011 Mains Physics - Semiconductor Electronics Question 82 English
A
(A), (B) and (D)
B
(C) only
C
(C) and (A)
D
(B) and (D)
3
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
An electron in the hydrogen atom jumps from excited state n to the ground state. The wavelength so emitted illuminates a photosensitive material having work function 2.75 eV. If the stopping potential of the photoelectron is 10 V, then the value of n is
A
2
B
3
C
4
D
5
4
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?
A
0.65 eV
B
1.9 eV
C
11.1 eV
D
13.6 eV