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A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]
- a)number of electrons emitted is a quarter ofthe initial number
- b)each emitted electron carries one quarter ofthe initial energy
- c)number of electrons emitted is half the initialnumber
- d)each emitted electron carries half the initialenergy
Correct answer is option 'A'. Can you explain this answer?
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A photoelectric cell is illuminated by a pointsource of light 1m away....
Power ∝ No. of electrons emitted (N)
Most Upvoted Answer
A photoelectric cell is illuminated by a pointsource of light 1m away....
Explanation:
When the point source of light is shifted from 1m to 2m, the intensity of light falling on the photoelectric cell decreases. This decreases the number of photons incident on the cell and hence the number of electrons emitted from the cell.
The number of electrons emitted from a photoelectric cell is directly proportional to the intensity of incident light. This is given by the photoelectric equation:
I = kNφ
Where I is the photoelectric current, N is the number of incident photons, φ is the work function of the metal and k is a constant.
From this equation, we can see that if the number of incident photons is reduced, the photoelectric current will also reduce.
Therefore, when the point source of light is shifted from 1m to 2m, the number of electrons emitted from the cell will decrease. The exact decrease in the number of electrons can be calculated using the inverse square law of radiation.
According to this law, the intensity of radiation from a point source is inversely proportional to the square of the distance from the source. Mathematically,
I ∝ 1/d^2
Where d is the distance from the source.
When the distance is doubled from 1m to 2m, the intensity of radiation will decrease to (1/2)^2 = 1/4th of its original value.
Therefore, the number of electrons emitted from the cell will also decrease to 1/4th of its original value.
Hence, option A is the correct answer.
When the point source of light is shifted from 1m to 2m, the intensity of light falling on the photoelectric cell decreases. This decreases the number of photons incident on the cell and hence the number of electrons emitted from the cell.
The number of electrons emitted from a photoelectric cell is directly proportional to the intensity of incident light. This is given by the photoelectric equation:
I = kNφ
Where I is the photoelectric current, N is the number of incident photons, φ is the work function of the metal and k is a constant.
From this equation, we can see that if the number of incident photons is reduced, the photoelectric current will also reduce.
Therefore, when the point source of light is shifted from 1m to 2m, the number of electrons emitted from the cell will decrease. The exact decrease in the number of electrons can be calculated using the inverse square law of radiation.
According to this law, the intensity of radiation from a point source is inversely proportional to the square of the distance from the source. Mathematically,
I ∝ 1/d^2
Where d is the distance from the source.
When the distance is doubled from 1m to 2m, the intensity of radiation will decrease to (1/2)^2 = 1/4th of its original value.
Therefore, the number of electrons emitted from the cell will also decrease to 1/4th of its original value.
Hence, option A is the correct answer.
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A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer?
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A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer?.
A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A photoelectric cell is illuminated by a pointsource of light 1m away. When the source isshifted to 2m then [2003]a)number of electrons emitted is a quarter ofthe initial numberb)each emitted electron carries one quarter ofthe initial energyc)number of electrons emitted is half the initialnumberd)each emitted electron carries half the initialenergyCorrect answer is option 'A'. Can you explain this answer?.
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