1
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct ?
A
The angular width of the central maximum will decrease.
B
The angular wifth of the central maximum will be unaffected.
C
Diffraction pattern is not observed on the screen in the case of electrons.
D
The angular width of the central maximum of the diffraction pattern will increase.
2
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
Ratio of longest wave lengths corresponding to Lyman and Balmer series in hydrogen spectrum is
A
$${7 \over {29}}$$
B
$${9 \over {31}}$$
C
$${5 \over {27}}$$
D
$${3 \over {23}}$$
3
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
For a normal eye, the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behinf the cornea is 20 D. Using this information, the distance between the retina and the cornea-eye lens can be estimated to be
A
1.67 cm
B
1.5 cm
C
5 cm
D
2.5 cm
4
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
A certain mass of Hydrogen is changed to Helium by the process of fusion. The mass defect in fusion reaction is 0.02866 u. The energy liberated per u is (given 1 u = 931 MeV)
A
6.675 MeV
B
13.35 MeV
C
2.67 MeV
D
26.7 MeV