1
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
A 5 watt source emits monochromatic light of wavelength 5000 $$\mathop A\limits^ \circ $$. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of
A
8
B
16
C
2
D
4
2
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
The frequency of a light wave in a material is 2 $$ \times $$ 1014 Hz and wavelength is 5000 $$\mathop A\limits^ \circ $$. The refractive index of material will be
A
1.50
B
3.00
C
1.33
D
1.40
3
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
The total energy of electron in the ground state of hydrogen atom is $$-$$ 13.6 eV. The kinetic energy of an electron in the first excited state is
A
6.8 eV
B
13.6 eV
C
1.7 eV
D
3.4 eV.
4
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is

AIPMT 2007 Physics - Semiconductor Electronics Question 65 English
A
an insulator
B
a metal
C
an n-type semiconductor
D
a p-type semiconductor.