In a biprism experiment the band width is 0.4 mm when the eye piece is at a distance of 1m from the slit. If the eye piece is moved through a distanc eof 25 cm towards the biprism, without changing any other arrangement, then the change in fringe width is

Options

A. 0.1 mm
B. 0.01 mm
C. 0.001 mm
D. 0.0001 mm

Answer

A

Explanation

`X_(1)=(lamdaD_(1))/(d),X_(2)=(lamdaD_(2))/(d)`
`(X_(2))/(X_(1))=(75)/(100)=(3)/(4)" "therefore X_(2)=0.3mm`
`therefore X_(1)-X_(2)=0.1mm`