Author Question: An 8.0-mW laser beam emits a cylindrical beam of single-wavelength sinusoidal light 0.90 mm in ... (Read 185 times)

nevelica · **on:** Jul 29, 2018

An 8.0-mW laser beam emits a cylindrical beam of single-wavelength sinusoidal light 0.90 mm in diameter. What is the rms value of the electric field in this laser beam?

(0 = 8.85 10-12 C2/N m2, 0 = 4 10-7 T m/A, c = 3.0 108 m/s)
A) 2200 N/C
B) 1000 N/C
C) 1100 N/C
D) 4100 N/C
E) 2000 N/C

Question 2

The magnitude of the magnetic field that a long and extremely thin current-carrying wire produces at a distance of 3.0 m from the center of the wire is 2.0 10-3 T. How much current is flowing through the wire? (0 = 4 10-7 T m/

A)
A) 30 mA
B) 190 mA
C) 19 mA
D) 380 mA