Question

A sound of intensity I is greater by 3.0103 dB from anoterh sound of intersity 10 nW cm^(-2). The absoulte value of intensity of sound level I is Wm^(-2) is :

Answer 1

Explanation:

Intensity of another sound =10

n

Wcm

−2

=10×10

−9

cm

2

w

=10×10

−9

10

−4

m

2

w

=10

−4

wm

−2

Now

If loudness of sound having Intently I=B

1

then,

B

1

=10log

10

−12

I

and if soundness of another sound =B

2

then,

B

2

=10log

10

−12

10

−4

=10log10

8

⇒B

2

=8×10=80

Since, B

1

is greater by B

2

by 3.0103dB

then,

⇒B

1

=3.0103+B

2

10log

10

−12

I

=3.0103+80

log

10

−12

I

=8.30103

⇒I=10

−12

×10

8.30103

⇒I=2×10

−4

Wm

−2