Most Important Selected Qs for JEE AdvancedPhysicsWave Optics
A thin paper of thickness 0.02 mm having refractive index 1.45 is pasted across one of the slits in a Young's double slit experiment. The paper transmits 4 / 9 of light falling on it. ( _ light =600 ~nm )
Options
- AAmplitude of light wave transmitted through the paper will be 2 / 3 times that of incident wave.
- BThe ratio of maximum and minimum intensity in the fringe pattern will be 25 .
- CThe total number of fringe crossing the centre if an identical paper is pasted on the other slit is 15 .
- DThe ratio of maximum and minimum intensity in the pattern will be 5 .
Correct answer
C. The total number of fringe crossing the centre if an identical paper is pasted on the other slit is 15 .
Step-by-step solution
aligned & I_ I_ = (a₁+a₂ )^2 (a₁-a₂ )^2 & a₁ a₂ = l₁ I₂ = 4 9 = 2 3 & I_ I_ =25 aligned If an identical paper is pasted across second slit shifted C.B.F. will back in central point. shift =( -1) tD d fringe width = n D d n = shift fringe width = ( -1) t =15 .