Chapter 21, Problem 21.133MP

(a)

Interpretation Introduction

Interpretation:

Number of photons per second emitted by the laser with a wavelength $660nm$ has to be determined.

Concept Introduction:

• Energy of a photon is given by $E=nh\upsilon =\frac{nhc}{\lambda }$ where h is the Plank’s constant is $6.626\times {10}^{-34}Js$, c is the speed of light $3\times {10}^{8}m/s$, $\lambda$ is the wavelength of light, n is the number of photons.

(b)

Interpretation Introduction

Interpretation:

The current in amperes that flows in the circuit of the solar cell if all the photons are absorbed by the cell and when each photon produces one electron has to be determined.

Concept introduction:

• Energy of a photon is given by $E=nh\upsilon =\frac{nhc}{\lambda }$ where h is the Plank’s constant and the value is $6.626\times {10}^{-34}Js$, c is the speed of light $3\times {10}^{8}m/s$, $\lambda$ is the wavelength of light, n is the number of photons.
• $E=Pt$, where E is the energy and P is the power at time t.
• $I=\frac{Q}{T}$, where I is the current, Q is the charge of the electron and t is the time.