# Write the Conditions on Path Difference Under Which (I) Constructive (Ii) Destructive Interference Occur in Young'S Double Slit Experiment. - Physics

Short Note

Write the conditions on path difference under which (i) constructive (ii) destructive interference occur in Young's double-slit experiment.

#### Solution

I_1 = intensity of light from slit 1
I_2 = intensity of light from slit 2
phase difference between 2 light waves = theta = (2xΔx)/lambda, where Δx = path difference resultant intensity I is given by,
I = I_1 + I_2 + 2sqrt(I_1I_2) cos theta
for constructive interference I should by maximum ⇒ theta = 1
theta = 2npi, n = "Integer"
2npi = (2piΔx)/lambda
Δx = nlambda
for distructive interference I should by minimum ⇒ cos theta = -1
theta = (2n + 1)pi , n = "Integer"
2npi = ((2n+1)piΔx)/lambda
Δx = ((2n+1)lambda)/2

Concept: Interference of Light Waves and Young’S Experiment
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