What is the intensity change when the intensity is increased from 1 mW/cm² to 4 mW/cm²?

What is the intensity change when the intensity is increased from 1 mW/cm² to 4 mW/cm²?

• A. -6 dB
• B. +6 dB
• C. +3 dB
• D. -3 dB

Answer: (B)

To determine the intensity change in decibels (dB) when the intensity increases from 1 mW/cm² to 4 mW/cm², we can use the formula for calculating intensity levels in decibels: \[ \text{dB change} = 10 \times \log_{10} \left(\frac{I_2}{I_1}\right) \] Here, \(I_2\) is the final intensity (4 mW/cm²), and \(I_1\) is the initial intensity (1 mW/cm²). Substituting the values into the formula: \[ \text{dB change} = 10 \times \log_{10} \left(\frac{4 mW/cm²}{1 mW/cm²}\right) = 10 \times \log_{10} (4) \] Calculating the logarithm: \[ \log_{10} (4) \approx 0.602 \] Now multiplying by 10: \[ \text{dB change} = 10 \times 0.602 \approx 6.02 \text{ dB} \] Since we often round to

To determine the intensity change in decibels (dB) when the intensity increases from 1 mW/cm² to 4 mW/cm², we can use the formula for calculating intensity levels in decibels:

[

\text{dB change} = 10 \times \log_{10} \left(\frac{I_2}{I_1}\right)

]

Here, (I_2) is the final intensity (4 mW/cm²), and (I_1) is the initial intensity (1 mW/cm²).

Substituting the values into the formula:

[

\text{dB change} = 10 \times \log_{10} \left(\frac{4 mW/cm²}{1 mW/cm²}\right) = 10 \times \log_{10} (4)

]

Calculating the logarithm:

[

\log_{10} (4) \approx 0.602

]

Now multiplying by 10:

[

\text{dB change} = 10 \times 0.602 \approx 6.02 \text{ dB}

]

Since we often round to