Most Important Selected Qs for JEE AdvancedPhysicsWaves and Sound
Paragraph: In an organ pipe (may be closed or open) of 99 cm length standing wave is setup, whose equation is given by longitudinal displacement =(0.1 ~mm ) 2 0.8 (y+1 ~cm ) 2 (400) t where y is measured from the top of the tube in meters and t in second. Here 1 cm is the end correction. Question: Equation of the standing wave in terms of excess pressure is (Bulk modulus of air B =5 10^5 ~N / m ^2 )
Options
- AP_ e x = (125 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (400 t )
- BP_ e x = (125 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (400 t )
- CP_ e x = (225 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (200 t )
- DP_ e x = (225 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (200 t )
Correct answer
A. P_ e x = (125 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (400 t )
Step-by-step solution
aligned P_ e x & =-B d d x & = (5 10^5 ) (0.1 10⁻³ ) 2 0.8 2 0.8 (y+1 ~cm ) 2 (400) t & = (125 N / m^2 ) 2 0.8 (y+1 ~cm ) 2 (400 t ) aligned