A 27 mW laser beam has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by [Given permittivity of space ∈0 = 9 × 10−12 SI units, Speed of light c = 3 × 108 m/s]
a.
1 kV/m
b.
2 kV/m
c.
1.4 kV/m
d.
0.7 kV/m
a.
1 kV/m
b.
2 kV/m
c.
1.4 kV/m
d.
0.7 kV/m
Question ID - 50361 | SaraNextGen Top Answer A 27 mW laser beam has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by [Given permittivity of space ∈0 = 9 × 10−12 SI units, Speed of light c = 3 × 108 m/s]
a.
1 kV/m
b.
2 kV/m
c.
1.4 kV/m
d.
0.7 kV/m
A 27 mW laser beam has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by [Given permittivity of space ∈0 = 9 × 10−12 SI units, Speed of light c = 3 × 108 m/s]
|
a. |
1 kV/m |
b. |
2 kV/m |
|
c. |
1.4 kV/m |
d. |
0.7 kV/m |
1 Answer
127 votes
Answer Key / Explanation : (c) -
Intensity of EM wave is given by
I = 
= 
C
= 
= 
× 9 × 10−12 × E2 × 3 ×108
E = 
× 103 kV/m
= 1.4 kV/m
127 votes
Answer Link
127