Question

Two points separated by a distance of 0.1 mm can just be observed using a microscope when light $\lambda = 600\: nm$ is used. If light of wavelength 480 nm is used, this limit of resolution becomes

• A. 0.8 mm
• B. 0.1 mm
• C. 0.125 mm
• D. 0.08 mm

Answer 1

Answer: (D)

0.08 mm

Answer 2

Resolving limit of microscope,
$y = \frac{\lambda}{2 \mu \sin \theta} or y \propto\lambda$
$\therefore \, \frac{y_{1}}{y_{2}} = \frac{\lambda _{1}}{\lambda _{2}}$
Here $, y_{1} = 0.1 mm , \lambda _{1} = 600 nm,$
$\lambda _{2 } = 480 nm , y_{2} = ?$
So, $\frac{0.1 mm}{y_{2} } = \frac{600 nm}{480 nm}$
or $, y_{2}= 0.08 mm$