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. In N-type semi-conductor current is due to
2. In p- type semiconductor, the acceptor level lies
3. Small drops of the same size are charges to V volt each. If n such drops coalesce
4. In Young’s double slit experiment, the fringe width is 1×10⁻⁴ m, if the distance
5. A body is thrown vertically upward in air when air resistance is taken into account

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