1
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of
A
collisions between the charged particles emitted from the cathode and the atoms of the gas
B
collision between different electrons of the atoms of the gas
C
excitation of electrons in the atoms
D
collision between the atoms of the gas
2
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
Two thin lenses of focal lengths f1 and f2 are in contact and coaxial. The power of the combination is
A
$${{{f_1} + {f_2}} \over 2}$$
B
$${{{f_1} + {f_2}} \over {{f_1}{f_2}}}$$
C
$$\sqrt {{{{f_1}} \over {{f_2}}}} $$
D
$$\sqrt {{{{f_2}} \over {{f_1}}}} $$
3
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly
A
1 $$ \times $$ 1014 Hz
B
20 $$ \times $$ 1014 Hz
C
10 $$ \times $$ 1014 Hz
D
5 $$ \times $$ 1014 Hz
4
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
If M(A; Z), Mp and Mn denote the masses of the nucleus $${}_Z^AX,$$ proton and neutron respectively in units of u (1 u = 931.5 MeV/c2) and BE represents its bonding energy in MeV, then
A
M(A, Z) = ZMp + (A $$-$$ Z)Mn $$-$$ BE
B
M(A, Z) = ZMp + (A $$-$$ Z)Mn + BE/c2
C
M(A, Z) = ZMp + (A $$-$$ Z)Mn $$-$$ BE/c2
D
M(A, Z) = ZMp + (A $$-$$ Z)Mn + BE