Question

Electromagnetic radiation from a 4.95mW laser is concentrated on a 1.05mm² area.

Options:
a) 4.71 W/m²
b) 4.71 mW/m²
c) 0.00471 W/m²
d) 0.00471 mW/m²

Answer 1

To find the intensity, one must convert the laser power to watts and the area to square meters, and then divide the power by the area, resulting in 4.71 W/m².

Step-by-step explanation:

To calculate the intensity of electromagnetic radiation from a laser in W/m², you can use the formula:

Intensity (I) = Power (P) / Area (A)

First, convert the given power from milliwatts to watts and the area from mm² to m²:

• Power: 4.95 mW = 4.95 x 10⁻³ W
• Area: 1.05 mm² = 1.05 x 10⁻⁶ m²

Next, perform the calculation:

I = (4.95 x 10⁻³ W) / (1.05 x 10⁻⁶ m²)

I = 4.71 x 10³ W/m²

Therefore, the correct option is (a) 4.71 W/m².