1
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
The resistances of the four arms P, Q, R and S in a Wheatstone's bridge are 10 ohm, 30 ohm, 30 ohm and 90 ohm, respectively. The e.m.f. and internal resistance of the cell are 7 volt and 5 ohm respectively. If the galvanometer resistance is 50 ohm, the current drawn from the celll will be
A
0.1 A
B
2.0 A
C
1.0 A
D
0.2 A
2
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths $${\lambda _1}$$ = 12000 $$\mathop A\limits^ \circ $$ and $${\lambda _2}$$ = 10000 $$\mathop A\limits^ \circ $$. At what minimum distance from the common central bright fringe on the screen 2 m from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other ?
A
4 mm
B
3 m
C
8 mm
D
6 mm
3
NEET 2013
MCQ (Single Correct Answer)
+4
-1
Change Language
For photoelectric emission from certain metal the cutoff frequency is $$\upsilon $$. If radiation of frequency 2$$\upsilon $$ impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass)
A
$$\sqrt {{{2h\upsilon } \over m}} $$
B
$$2\sqrt {{{h\upsilon } \over m}} $$
C
$$\sqrt {{{h\upsilon } \over {\left( {2m} \right)}}} $$
D
$$\sqrt {{{h\upsilon } \over m}} $$
4
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.