Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per sec. on the average at a target irradiated by this beam is
A
3 $$ \times $$ 1016
B
$$9 \times {10^{15}}$$
C
$$3 \times {10^{19}}$$
D
$$9 \times {10^{17}}$$
2
AIPMT 2009
MCQ (Single Correct Answer)
+4
-1
The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement?
A
Curves (a) and (b) represent incident radiations of same frequency but of different intensities.
B
Curves (b) and (c) represent incident radiations of different frquencies and different intensities.
C
Curves (b) and (C) represent incident radiations of same frequency having same intensity.
D
Curves (a) and (b) represent incident radiations of different frequencies and different intensities
3
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the
A
infrared region
B
X-ray region
C
Ultraviolet region
D
Visible region
4
AIPMT 2008
MCQ (Single Correct Answer)
+4
-1
A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 $$ \times $$ 106 m s$$-$$1. The velocity of the particle is
