Multiple Choice
A 20 W laser beam, with an initial diameter of 2.0 mm, spreads out to a diameter of 2.0 m after traveling 10,000 m. What is the initial Erms of the beam?
A) 4.9 × 104 V/m
B) 2.5 × 103 V/m
C) 1.2 × 103 V/m
D) 1.9 × 102 V/m
E) 1.7 × 102 V/m
Correct Answer:
Verified
Correct Answer:
Verified
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