A sound level meter placed in front of the loudspeaker of a 60W and audio system reads 70dB. All else being equal, when placed in front of 120W system, the meter will read ('x' in dB). Write

Question

A sound level meter placed in front of the loudspeaker of a 60W and audio system reads 70dB. All else being equal, when placed in front of 120W system, the meter will read ('x' in dB). Write $\frac{x + 7}{10}$ as your answer. ( $x$ is in nearest integer and $lo g_{10} 2 = 0.30$ ).

Answer:

8

Solution:

$L = 70 + 10 lo g_{10} \frac{120}{60} = 70 + 10 lo g_{10} 2 = 73 d B$ .

So $x = 73$ and $\frac{x + 7}{10} = 8$ .

TestHub · Accepted Answer

L = 70 + 10 lo g 10 ​ 60 120 ​ = 70 + 10 lo g 10 ​ 2 = 73 d B . So x = 73 and 10 x + 7 ​ = 8 .

Physics - Sound Wave Question with Solution | TestHub

Doubts & Discussion

JEE Advanced 2027 (Class 12)