AMU Engineering 2018 solved paper Solved Paper

Given, path difference, Δx=1.8m
v1=1000Hz,vsound =360m∕s
According to the question, For maximum intensity of sound at point P,
Path difference, x2−x1=nλ
or Δx=nλ‌‌‌[ where, λ= wavelength of the sound ]
⇒Δx=n

v

v

........(i)
[∵λ=

v

v

(frequency )]
For Ist case, v1=n×

360

1.8

1000=n×

360

1.8

........(ii)
For IInd case, v2=(n+1)

360

1.8

.........(iii)
v2=n.

360

1.8

+

360

1.8

=1000+200=1200Hz [From Eq. (ii) ]