Chapter 7, Problem 7A.7AE

(i)

Interpretation Introduction

Interpretation:

The number of photons emitted each second if the power of the sodium lamp is $1.0\text{W}$ has to be calculated.

Concept introduction:

The small packet of energy is known as the quanta.  Light is emitted in the form of quanta or photons.  The formula for energy of photon is given by the expression,

    $E=\frac{hc}{\lambda }$

Where,

• $\lambda$ is the de Broglie wavelength.
• $h$ is the Planck’s constant.
• $c$ is the speed of light.
• $E$ is the energy of photon.

(ii)

Interpretation Introduction

Interpretation:

The number of photons emitted each second if the power of the sodium lamp is $100\text{W}$ has to be calculated.

Concept introduction:

The small packet of energy is known as the quanta.  Light is emitted in the form of quanta or photons.  The formula for energy of photon is given by the expression,

    $E=\frac{hc}{\lambda }$

Where,

• $\lambda$ is the de Broglie wavelength.
• $h$ is the Planck’s constant.
• $c$ is the speed of light.
• $E$ is the energy of photon.