Question

If the level of intensity of any tone is 20 decibel, then the intensity will be equal to

(A) 10 W/m²

(B) 10^-10 W/m²

(C) 10¹⁰ W/m²

(D) none of these

Answer 1

Correct option is (B) 10^-10 W/m²

\(\beta = 10 \log\frac{I}{I_0}\)

\(20= 10\log\left(\frac I{10^{-12}}\right)\)

\(I = 10^{-10} \ W/m^2\)