1
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
Three point charges +q, $$-$$ 2q and + q are placed at points (x = 0, y = a, z = 0), (x = 0, y = 0, z = 0) and (x = $$a$$, y = 0, z = 0) respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are
A
$$\sqrt 2 qa$$ along the line joining points (x = 0, y = 0, z = 0) and (x = $$a$$, y = a, z = 0)
B
q$$a$$ along the line joining points (x = 0, y = 0, z = 0) and (x = $$a$$, y = a, z = 0)
C
$$\sqrt 2 qa$$ along +x direction
D
$$\sqrt 2 qa$$ along +y direction.
2
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
Monochromatic light of frequency 6.0 $$ \times $$ 1014 Hz is produced by a laser. The power emitted is 2 $$ \times $$ 10$$-$$3 W. The number of photons emitted, on the average, by the source per second is
A
5 $$ \times {10^{16}}$$
B
5 $$ \times {10^{17}}$$
C
5 $$ \times {10^{14}}$$
D
5 $$ \times {10^{15}}$$
3
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
A beam of electron passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move
A
in a circular orbit
B
along a parabolic path
C
along a straight line
D
in an elliptical orbit.
4
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