High power lasers in factories are used to cut through cloth and metal (Figure P

Question

High power lasers in factories are used to cut through cloth and metal (Figure P34.23). One such laser has a beam diameter of 1.50 mm and generates an electric field having an amplitude of 0.650 MV/m at the target. (a) Find the amplitude of the magnetic field produced. 1.66 Your response differs from the correct answer by more than 10%. Double check your calculations. mT (b) Find the intensity of the laser. 775 Your response differs from the correct answer by more than 10%. Double check your calculations. MW/m^2 (c) Find the power delivered by the laser. 1200 Your response differs from the correct answer by more than 10%. Double check your calculations. W

Explanation / Answer

a)For electromagnetic radiation,

Em/Bm = c

Bm = Em/c

Bm = 0.650 x 10^6/3 x 10^8 = 0.217 x 10^-2 = 0.00217 T

Hence, Bm = 0.00217 T

b)Intensity is related to electric field as:

I = Em^2/2 c u0

I = (0.65 x 10^6)^2/2 x 3 x 10^8 x 4 pi x 10^-7 = 5.61 x 10^8 W/m^2

I = 5.61 x 10^8 W/m^2 = 561 MW/m^2

Hence, I = 561 MW/m^2

c)I = P/A

P = I x A

P = 5.61 x 10^8 x 3.14 (1.5 x 10^-3/2)^2 = 990.87 W

Hence, P = 990.87 W

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.