Advertisements
Advertisements
प्रश्न
The work function for a metal surface is 4.14 eV. The threshold wavelength for this metal surface is ______.
विकल्प
4125 Å
2062.5 Å
3000 Å
6000 Å
Advertisements
उत्तर
The work function for a metal surface is 4.14 eV. The threshold wavelength for this metal surface is 3000 Å.
Explanation:
w = 4.14 eV
l0 = ?
w = `"hc"/lambda_0`
`lambda_0 = "hc"/"w"`
`lambda_0 = (12,375)/("w"("ev"))` Å
`lambda_0 = (12,375)/4.14` Å
`lambda_0 = 2,985` Å
`lambda_0 ≈ 3,000` Å
APPEARS IN
संबंधित प्रश्न
Light of intensity 10−5 W m−2 falls on a sodium photo-cell of surface area 2 cm2. Assuming that the top 5 layers of sodium absorb the incident energy, estimate time required for photoelectric emission in the wave-picture of radiation. The work function for the metal is given to be about 2 eV. What is the implication of your answer?
The following graph shows the variation of photocurrent for a photosensitive metal :
(a) Identify the variable X on the horizontal axis.
(b) What does the point A on the horizontal axis represent?
(c) Draw this graph for three different values of frequencies of incident radiation v1, v2 and v3 (v1 > v2 > v3) for same intensity.
(d) Draw this graph for three different values of intensities of incident radiation I1, I2 and I3 (I1 > I2 > I3) having same frequency.
Show that it is not possible for a photon to be completely absorbed by a free electron.
The work function of a metal is 2.5 × 10−19 J. (a) Find the threshold frequency for photoelectric emission. (b) If the metal is exposed to a light beam of frequency 6.0 × 1014 Hz, what will be the stopping potential?
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
The electric field associated with a light wave is given by `E = E_0 sin [(1.57 xx 10^7 "m"^-1)(x - ct)]`. Find the stopping potential when this light is used in an experiment on photoelectric effect with the emitter having work function 1.9 eV.
Define the terms "stopping potential' and 'threshold frequency' in relation to the photoelectric effect. How does one determine these physical quantities using Einstein's equation?
In the case of photoelectric effect experiment, explain the following facts, giving reasons.
The photoelectric current increases with increase of intensity of incident light.
Do all the electrons that absorb a photon come out as photoelectrons?
A metallic plate exposed to white light emits electrons. For which of the following colours of light, the stopping potential will be maximum?
Which of the following options represents the variation of photoelectric current with property of light shown on the x-axis?
