Single Choice

$$A$$ and $$B$$ are two metals with threshold frequencies $$1.8\times 10^{14}\ $$$$Hz$$ and $$2.2\times 10^{14}\ $$$$Hz$$. Two identical photons of energy $$0.825\ $$$$eV$$ each are incident on them. Then photoelectrons are emitted by: (Taking $$h=6.626\times 10^{-34}\ $$$$Js$$)

A$$B$$ alone
B$$A$$ alone
Correct Answer
CNeither $$A$$ nor $$B$$
DBoth $$A$$ and $$B$$

Solution

Frequency of photon corresponding to energy $$0.825\ eV =\dfrac{0.825\times 1.6\times 10^{-19}}{6.626\times 10^{-34}}=1.99\times 10^{14}\ Hz$$
Since, this frequency is greater than the frequency required for emission of photoelectrons from metal $$A$$, photoelectrons are emitted from metal $$A$$ but not from metal $$B$$.

SIMILAR QUESTIONS

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In photoelectric effect, the number of photo-electrons emitted is proportional to:

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A certain metallic surface is illuminated with monochromatic light of wavelength, $$\lambda$$. The stopping potential for photo-electric current for this light is $$3V_0$$. If the same surface is illuminated with light of wavelength $$2\lambda$$, the stopping potential is $$V_0$$. The threshold wavelength for this surface for photo-electric effect is:

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When a metallic surface is illuminate with radiation of wavelength $$\lambda$$, the stopping potential is V. If the same surface is illuminated with radiation of wavelength $$2\lambda$$, the stopping potential is $$\displaystyle\frac{V}{4}$$. The threshold wavelength for the metallic surface is:

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The photoelectric work function for a metal is 6×10−19J. Threshold wavelength is equal to _______________.

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The work function of a metal is $$2\cdot 5\times { 10 }^{ -9 }J$$. (a) Find the threshold frequency for photoelcectric emission. (b) If the metal is exposed to a light beam of frequency $$6\cdot 0\times { 10 }^{ 14 }Hz$$, what will be the stopping potential ?

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The work function of a photoelectric material is 4.0 eV. (a) What is the threshold wavelength ?(b) Find the wavelength of light for which the stopping potential is 2.5 V.

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When a surface 1 cm thick is illuminated with light of wave length $$\lambda$$ the stopping potential is $$V_{0}$$ ,but when the same surface is illuminated by light of wavelength 3$$\lambda$$ , the stopping potential is $$\dfrac{V_{0}}{6}$$. The threshold wavelength for metallic surface is

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When the electromagnetic radiations of frequencies $$4 \times 10^{15}\ Hz$$ and $$6\times 10^{15}\ Hz$$ fall on the same metal, in different experiments, ratio of maximum kinetic energy of electrons liberated is $$1:3$$. The threshold frequency for the metal is:

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