A 24. 0-mw (milli-watts) laser puts out a narrow cylindrical beam 2. 00 mm in diameter. The average rms electric field is 2.82N/C.
The Average rms Electric Field is the square root of the mean value of electric field.
Given:
Power of beam = 24mW = 0.024W
Diameter of beam = 2mm = 0.002m
Radius of beam = 1mm = 0.001m
∴ Area Of beam = 22/7 × (radius)²
⇒ Area Of beam = 22/7 × (0.001)²
⇒ Area Of beam = 3.14 m²
∴ Intensity of Beam is the power per unit area where the beam spreads.
Intensity of Beam = Power / Area
⇒ Intensity of Beam = 0.024 / 3.14
⇒ Intensity of Beam = 0.075 W/m²
The average value of RMS for Electric field can be calculated by:
Erms = [tex]\sqrt{Intensity / (speed of light) (permmitivitty of medium)}[/tex]
Erms = 0.075 / 3 × 10⁸ × 8.85 × 10⁻¹²
Erms = 2.82 N/C
Hence, The average value of rms electric field is 2.82N/C
Learn more about RMS value here, https://brainly.com/question/13991073
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