The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work functions 5.01 eV, when ultraviolet light of 200 nm falls on it, must be
A
2.4 V
B
$$-$$ 1.2 V
C
$$-$$ 2.4 V
D
1.2 V
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 2009
MCQ (Single Correct Answer)
+4
-1
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
$$9 \times {10^{17}}$$
4
AIPMT 2009
MCQ (Single Correct Answer)
+4
-1
The number of photo electrons emitted for light of a frequency $$\upsilon $$ (higher than the threshold frequency $${\upsilon _0}$$) is proportional to
A
threshold frequency $$\left( {{\upsilon _0}} \right)$$
B
intensity of light
C
frequency of light $$\left( {{\upsilon _0}} \right)$$
