91Ó°ÊÓ

The power transported per unit area is known as the intensity ( I ) .

The formula used to calculate the intensity ( I ) is:

$I=\frac{P}{A}$

Where, $A$is area measured in the direction perpendicular to the energy and$P$ is the power in watts.

The formula used to determine the amplitude of electric and magnetic fields of the wave are:

$$\begin{gathered} E_{max}=\sqrt{\frac{2I}{{\mathrm{Î\mu }}_{0}c}} \\ {B}_{max}=\frac{E_{max}}{c} \end{gathered}$$

Where,${\mathrm{Î\mu }}_0=8.85×{10}^{-12}{C}^2/N·m^2$ and c is the speed of light that is equal to $3.0×{10}^{8}m/s$.

The energy of flows through the area is related to time as $\left(F\right)=Pt$.

Given that,

$$\begin{gathered} P=2×{10}^{12}\mathrm{W} \\ t=4×{10}^{-9}\mathrm{s} \end{gathered}$$

The energy of flows through the area is related to time is

$\left(F\right)=Pt$

Substitute values in above equation

$$\begin{gathered} F=\left(2×{10}^{12}\right)\left(4×{10}^{-9}\right) \\ =8\mathrm{kJ} \end{gathered}$$

Hence,$8\mathrm{kJ}$ of energy is given to the cell during pulse.

Given that,

$$\begin{gathered} P=2×{10}^{12}W \\ d=5\mathrm{μ}m \end{gathered}$$

The formula used to calculate the intensity$\left(I\right)$ is:

$I=\frac{P}{A}$

Substitute the values

$$\begin{gathered} I=\frac{2×{10}^{12}}{\mathrm{π}\left({\displaystyle \frac{5×{10}^{-6}}{2}}\right)} \\ =\frac{2×{10}^{12}}{19.63×{10}^{-12}} \\ ={10}^{21}\mathrm{W}/{\mathrm{m}}^2 \end{gathered}$$

Hence, the amount of intensity delivered to cell is ${10}^{21}\mathrm{W}/{\mathrm{m}}^2$.

The maximum value of electric field is:

$E_{max}=\sqrt{\frac{2I}{{\mathrm{Î\mu }}_{0}c}}$

Substitute the values

$$\begin{gathered} E_{max}=\sqrt{\frac{2×\left({10}^{21}\right)}{\left(8.85×{10}^{-12}\right)\left(3×{10}^8\right)}} \\ =8.7×{10}^{11}\mathrm{V}/\mathrm{m} \end{gathered}$$

The amplitude of magnetic field is:

$B_{max}=\frac{E_{max}}{c}$

Substitute the values

$$\begin{gathered} B_{max}=\frac{8.7×{10}^{11}}{3×{10}^8} \\ =2.9×{10}^3\mathrm{T} \end{gathered}$$

Hence, the maximum values of the electric and magnetic fields in the pulse are$8.7×{10}^{11}\mathrm{V}/\mathrm{m}$ and$2.9×{10}^3\mathrm{T}$ respectively.