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The number of photons of wavelength of 540 nm emitted per second by an electric bulb of power 100 W is (given h=6×10⁻³⁴ J-s)
Options
(a) 100
(b) 1000
(c) 3×10²⁰
(d) 3×10¹⁸
Correct Answer:
3×10²⁰
Explanation:
Power = nhc / ( × t)
⇒ 100 = [n × (6 × 10⁻³⁴) × (3 × 10⁸)] / (540 × 10⁹ × 1)
⇒ n × 18 × 10⁻²⁶ / 540 × 10⁻⁹ = 100
⇒ n = 100 × 540 × 10⁻⁹ / 18 × 10⁻²⁶ = 3 x 10²⁰
Related Questions: - A train of mass 2x 10⁵ kg has a constant speed of 20 m/s up a hill inclined
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- Certain quantity of water cools from 70⁰ C to 60⁰C in the first 5 minutes and to 54⁰C
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Topics: Dual Nature of Matter and Radiation
(150)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A train of mass 2x 10⁵ kg has a constant speed of 20 m/s up a hill inclined
- Two sound waves of wavelengths 5m and 6m formed 30 beats in 3 seconds
- Certain quantity of water cools from 70⁰ C to 60⁰C in the first 5 minutes and to 54⁰C
- A point charge q is situated at a distance r on axis from one end of a thin
- A round disc of moment of inertia i₂ about its axis perpendicular to its plane
Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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