91Ó°ÊÓ

Wavelength $\mathrm{λ}=550nm$

We know that angular resolution of telescope is given by,

${\mathrm{θ}}_{min}=\frac{1.22\mathrm{λ}}{D}$

Two objects are said to be marginally resolvable if localid="1649406994660" $\mathrm{Î\pm }={\mathrm{θ}}_{min}$and are said to be resolvable if $\mathrm{Î\pm }>{\mathrm{θ}}_{min}$

Therefore, Decreasing wavelength decreases ${\mathrm{θ}}_{min}$which makes role="math" localid="1649406982932" $\mathrm{Î\pm }>{\mathrm{θ}}_{min}$so the resolution is improved.

The lens has same diameter but a different focal length.

We know that angular resolution of telescope is given by,

${\mathrm{θ}}_{min}=\frac{1.22\mathrm{λ}}{D}$

objective lens have same focal length but a different diameter.

Angular resolution of telescope is,

${\mathrm{θ}}_{min}=\frac{1.22\mathrm{λ}}{D}$

Two objects are said to be marginally resolvable if $\mathrm{Î\pm }={\mathrm{θ}}_{min}$and are said to be resolvable if localid="1649406939654" $\mathrm{Î\pm }>{\mathrm{θ}}_{min}$

Increasing D (as lens size is increased) decreases ${\mathrm{θ}}_{min}$which makes $\mathrm{Î\pm }>{\mathrm{θ}}_{min}$ .

eyepiece of different magnification.

Angular resolution of telescope is,

${\mathrm{θ}}_{min}=\frac{1.22\mathrm{λ}}{D}$

Magnification plays no role in the above formula.