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A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be?
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A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a...
Calculation of Photoelectric Current
Given:
- Lamp power (P) = 2mW = 2 * 10^-3 W
- Wavelength of emitted light (λ) = 5000 Å (angstrom) = 5000 * 10^-10 m
- Work function of metallic surface (Φ) = 1.9 eV
- Quantum efficiency (η) = 5%
Step 1: Calculate the energy of the incident photons
The energy (E) of a photon can be calculated using the formula:
E = hc/λ
where h is Planck's constant (6.626 x 10^-34 J.s) and c is the speed of light (3 x 10^8 m/s).
E = (6.626 x 10^-34 J.s * 3 x 10^8 m/s) / (5000 * 10^-10 m)
E ≈ 3.9788 x 10^-19 J
Step 2: Calculate the number of photons incident on the surface per second
The number of photons (N) incident on the surface per second can be calculated using the formula:
N = P/E
where P is the power of the lamp.
N = (2 * 10^-3 W) / (3.9788 x 10^-19 J)
N ≈ 5.0245 x 10^15 photons/s
Step 3: Calculate the number of photoelectrons emitted per second
The number of photoelectrons emitted per second (n) can be calculated using the formula:
n = η * N
where η is the quantum efficiency.
n = (5% * 5.0245 x 10^15 photons/s)
n ≈ 2.5123 x 10^14 electrons/s
Step 4: Calculate the photoelectric current
The photoelectric current (I) can be calculated using the formula:
I = n * e
where e is the charge of an electron (1.6 x 10^-19 C).
I = (2.5123 x 10^14 electrons/s) * (1.6 x 10^-19 C/electron)
I ≈ 4.0197 x 10^-5 A
Therefore, the photoelectric current will be approximately 4.0197 x 10^-5 A.
Given:
- Lamp power (P) = 2mW = 2 * 10^-3 W
- Wavelength of emitted light (λ) = 5000 Å (angstrom) = 5000 * 10^-10 m
- Work function of metallic surface (Φ) = 1.9 eV
- Quantum efficiency (η) = 5%
Step 1: Calculate the energy of the incident photons
The energy (E) of a photon can be calculated using the formula:
E = hc/λ
where h is Planck's constant (6.626 x 10^-34 J.s) and c is the speed of light (3 x 10^8 m/s).
E = (6.626 x 10^-34 J.s * 3 x 10^8 m/s) / (5000 * 10^-10 m)
E ≈ 3.9788 x 10^-19 J
Step 2: Calculate the number of photons incident on the surface per second
The number of photons (N) incident on the surface per second can be calculated using the formula:
N = P/E
where P is the power of the lamp.
N = (2 * 10^-3 W) / (3.9788 x 10^-19 J)
N ≈ 5.0245 x 10^15 photons/s
Step 3: Calculate the number of photoelectrons emitted per second
The number of photoelectrons emitted per second (n) can be calculated using the formula:
n = η * N
where η is the quantum efficiency.
n = (5% * 5.0245 x 10^15 photons/s)
n ≈ 2.5123 x 10^14 electrons/s
Step 4: Calculate the photoelectric current
The photoelectric current (I) can be calculated using the formula:
I = n * e
where e is the charge of an electron (1.6 x 10^-19 C).
I = (2.5123 x 10^14 electrons/s) * (1.6 x 10^-19 C/electron)
I ≈ 4.0197 x 10^-5 A
Therefore, the photoelectric current will be approximately 4.0197 x 10^-5 A.
Community Answer
A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a...
Is it 25×10^13
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A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be?
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A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be?.
A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A lamp of 2mW emits light of wavelength 5000 angstrom light falls on a metallic surface having a function of 1.9 EV if the quantum efficiency is 5% the photo electric current will be?.
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