in an experimental set up to study the photoelectric effect a point soure fo light of power `3.2xx10^(-3)` W was taken. The source can emit monoenergetic photons of energy 5eV and is located at a distance of 0.8 m from the centre of a stationary metallic sphere of work-function 3.0 eV. The radius of the sphere is `r = 8..10^(-3)` m. The efficiency of photoelectric emission is one for every `10^6` incident photons. Based on the information given above answer the questions given below. (Assume that the sphere is isolated and photoelectrons are instantly swepts away after the emission).
It was observed that after some time emission of photoelectrons from the sphere stopped. Charge on the sphere when the photon emission stops is
in an experimental set up to study the photoelectric effect a point soure fo light of power `3.2xx10^(-3)` W was taken. The source can emit monoenergetic photons of energy 5eV and is located at a distance of 0.8 m from the centre of a stationary metallic sphere of work-function 3.0 eV. The radius of the sphere is `r = 8..10^(-3)` m. The efficiency of photoelectric emission is one for every `10^6` incident photons. Based on the information given above answer the questions given below. (Assume that the sphere is isolated and photoelectrons are instantly swepts away after the emission).
It was observed that after some time emission of photoelectrons from the sphere stopped. Charge on the sphere when the photon emission stops is
It was observed that after some time emission of photoelectrons from the sphere stopped. Charge on the sphere when the photon emission stops is
A
`16piepsilon_0^r` coulomb
B
`8piepsilon_0^r` coulomb
C
`15piepsilon_0^r` coulomb
D
`20piepsilon_0^r` coulomb
Text Solution
Verified by Experts
The correct Answer is:
B
`K_(max)` is 2 eV. Hence, stopping potential is 2V.
Photoemission stops when potential of sphere
becomes 2V.
`:. 2 =(q)/(4piepsilon_0r)`
`:. q = 8piepsilon_0 r.`
Photoemission stops when potential of sphere
becomes 2V.
`:. 2 =(q)/(4piepsilon_0r)`
`:. q = 8piepsilon_0 r.`
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in an experimental set up to study the photoelectric effect a point soure fo light of power 3.2xx10^(-3) W was taken. The source can emit monoenergetic photons of energy 5eV and is located at a distance of 0.8 m from the centre of a stationary metallic sphere of work-function 3.0 eV. The radius of the sphere is r = 8..10^(-3) m. The efficiency of photoelectric emission is one for every 10^6 incident photons. Based on the information given above answer the questions given below. (Assume that the sphere is isolated and photoelectrons are instantly swepts away after the emission). Time after which photoelectric emission stops is
in an experimental set up to study the photoelectric effect a point soure fo light of power 3.2xx10^(-3) W was taken. The source can emit monoenergetic photons of energy 5eV and is located at a distance of 0.8 m from the centre of a stationary metallic sphere of work-function 3.0 eV. The radius of the sphere is r = 8..10^(-3) m. The efficiency of photoelectric emission is one for every 10^6 incident photons. Based on the information given above answer the questions given below. (Assume that the sphere is isolated and photoelectrons are instantly swepts away after the emission). Time after which photoelectric emission stops is
A
100s
B
121s
C
111s
D
141s
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A
`6.63 Å`
B
`8.69 Å`
C
`2 Å`
D
`5.26 Å`
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A
`10^(3)`
B
`10^(4)`
C
`5xx10^(4)`
D
`10^(5)`