1
AIPMT 2004
MCQ (Single Correct Answer)
+4
-1
In semiconductors at a room temperature
A
the valence band is partially empty and the conduction band is partially filled
B
the valence band is completely filled and the conduction band is partially filled
C
the valence band is completely filled
D
the conduction band is completely empty
2
AIPMT 2004
MCQ (Single Correct Answer)
+4
-1
A wheel having moment of inertia 2 kg m2 about its vertical axis, rotates at the rate of 60 rpm about this axis. The torque which can stop the wheel's rotation in one minute would be
A
$${{2\pi } \over {15}}$$ N m
B
$${\pi \over {12}}$$ N m
C
$${\pi \over {15}}$$ N m
D
$${\pi \over {18}}$$ N m
3
AIPMT 2004
MCQ (Single Correct Answer)
+4
-1
The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be
A
2R
B
4R
C
$${1 \over 4}$$R
D
$${1 \over 2}$$R
4
AIPMT 2004
MCQ (Single Correct Answer)
+4
-1
If $$\lambda $$m denotes the wavelength at which the radioactive amission from a black body at a temperature TK is maximum, then
A
$${\lambda _m}\, \propto \,{T^4}$$
B
$${\lambda _m}$$ is independent of T
C
$${\lambda _m}$$ $$ \propto $$ T
D
$${\lambda _m}\, \propto \,{T^{ - 1}}$$