Advertisements
Advertisements
प्रश्न
Calculate the energies of the photons associated with the following radiation:
- violet light of 413 nm
- X-rays of 0.1 nm
- radio waves of 10 m
Advertisements
उत्तर
E = hv
E = `"hc"/λ` in Joule
E = `"hc"/(λe)` in eV
i. violet light of 413 nm
E = `(6.625 xx 10^-34 xx 3 xx 10^8)/(413 xx 10^-9 xx 1.6 xx 10^-19)`
= `19.875/660.8 xx 10^-26 xx 10^28`
= 0.032 × 102
E = 3 eV
ii. X-rays of 0.1 nm
E = `(6.625 xx 10^-34 xx 3 xx 10^8)/(0.1 xx 10^-9 xx 1.6 xx 10^-19)`
= `(19.875 xx 10^-26)/(0.16 xx 10^-28)`
= 124.24 × 102
E = 12424 eV
iii. radio waves of 10 m
E = `(6.625 xx 10^-34 xx 3 xx 10^8)/(10 xx 1.6 xx 10^-19)`
= `19.875/1.6 xx 10^-26 xx 10^-1 xx 10^19`
E = 1.24 × 10−7 eV
APPEARS IN
संबंधित प्रश्न
In photoelectric emission, a radiation whose frequency is 4 times threshold frequency of a certain metal is incident on the metal. Then the maximum possible velocity of the emitted electron will be
Two radiations with photon energies 0.9 eV and 3.3 eV respectively are falling on a metallic surface successively. If the work function of the metal is 0.6 eV, then the ratio of maximum speeds of emitted electrons in the two cases will be
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is
Mention the different types of photocells.
Define stopping potential.
Explain how frequency of incident light varies with stopping potential.
Obtain Einstein’s photoelectric equation with the necessary explanation.
Give the applications photocell.
Calculate the maximum kinetic energy and maximum velocity of the photoelectrons emitted when the stopping potential is 81 V for the photoelectric emission experiment.
When a light of frequency 9 × 1014 Hz is incident on a metal surface, photoelectrons are emitted with a maximum speed of 8 × 105 ms−1. Determine the threshold frequency of the surface.
