Question

In a Young's double slit experiment, the intensities at two points, for the path respectively If $I_0$ denotes the intensity produced by each one of the individual slits, then $\frac{I_1+I_2}{I_0}=$_______

Answer 1

The correct answer is 3.
I=4I0​cos2(2Δϕ​)
I1​=4I0​cos2(4π​)=2I0​
I2​=4I0​cos2(32π​)=I0​
⇒I0​I1​+I2​​=3