The number of photons of wavelength of 540 nm emitted per second by an electric bulb

⇦

⇨

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:

1. If in a nuclear fusion process, the masses of the fusing nuclei be m₁ and m₂
2. In photoelectric emission process from a metal of work function
3. The conducting loop in the form of a circle is placed in a uniform magneitc field
4. An electric charge 10⁻³ μC is placed at the origin (0,0) of X-Y co-ordinate system.
5. Two particles A and B having equal charges, after being accelerated

Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends