The displacement of the two coherent waves at any point is y1 = a cos(ωt) and y2 = a cos(ωt + ϕ). The intensity of both waves is Io. When they are superimposed the resultant intensity is equal to:
1
\(4I_ocos^2\left ( \frac{\phi}{2} \right )\)
2
\(4I_osin^2\left ( \frac{\phi}{2} \right )\)
3
4Io
4
None of these