Question

The minimum non-zero distance on screen from central maxima where both the wave are going to produce maxima together

• A. $2000\mu m$
• B. $3600\mu m$
• C. $4320\mu m$
• D. $2160\mu m$

Answer 1

Answer: (B)

$3600\mu m$

Since the beams are interfering we have,
$n{\lambda }_1=m{\lambda }_2$
$⟹n\times 600nm=m\times 720nm$
$⟹n\times 10=m\times 12$
Hence $n=6andm=5$
Also we have $n\lambda =\frac{dy}{D}$
$⟹y=\frac{n\lambda D}{d}$

$⟹y=3600\mu m$