UPSEE Solved Model Paper 3

Intensity α (Amplitude)2
⇒ I α A2
When two waves (beams) of amplitude A1 and A2 superimpose, at maxima and minima, the amplitude of the resulting wave are (A1+A2) and (A1−A2), respectively.
If the maximum and minimum possible intensities are Imax and Imin, respectively. Then,
Imax α (A1+A2)2 and
Imin α (A1−A2)2
⇒

Imax

Imin

= (

A1+A2

A1−A2

)2
= {

A1 A2 +1

A1 A2 −1

}2
where,

A1

A2

= √

I

4I

=

1

2

Imax

Imin

=

9

1

⇒ Imax = 9I and Imin = I