AP EAPCET 23-Aug-2021 Shift 2 Paper

Given, the ratio of amplitudes of two interfering waves is 4:3
i.e.,

A1

A2

=

4

3

We know that, intensity of wave is proportional to square of amplitude.
∴

Imax

Imin

=(

Amax

Amin

)2, where maximum and minimum amplitudes are
Amax=A1+A2
and Amin=A1−A2
Substituting the values, we get

Imax

Imin

=(

A1+A2

A1−A2

)2 Multiplying and dividing by A22 in RHS, we get.

Imax

Imin

=(

A1 A2 +1

A1 A2 −1

)2 =(

4 3 +1

4 3 −1

)2 =(

7

1

)2=

49

1