What should be the distance from the objective lens of an object to focus it properly so that the final image is formed at the least distance of clear vision?

Question

What should be the distance from the objective lens of an object to focus it properly so that the final image is formed at the least distance of clear vision? (A) 1.1cm (B) 2.2cm (C) 3.3cm (D) 4.4cm

Tardigrade Admin · Accepted Answer

For eyepiece, VE=-25cm,fE=+5cm ⇒ uE=-4.17cm=-4.2cm L=v0+|uE|=12.2cm here v0=8cm f0=+1cm⇒ u0=-1.1cm

Q. What should be the distance from the objective lens of an object to focus it properly so that the final image is formed at the least distance of clear vision?

$1.1 c m$

$2.2 c m$

$3.3 c m$

$4.4 c m$

For eyepiece, $V_{E} = - 25 c m, f_{E} = + 5 c m$
$\Rightarrow u_{E} = - 4.17 c m = - 4.2 c m$
$L = v_{0} + ∣ u_{E} ∣ = 12.2 c m$
here $v_{0} = 8 c m$
$f_{0} = + 1 c m \Rightarrow u_{0} = - 1.1 c m$

Q. What should be the distance from the objective lens of an object to focus it properly so that the final image is formed at the least distance of clear vision?

1.1cm

2.2cm

3.3cm

4.4cm

For eyepiece, VE​=−25cm,fE​=+5cm ⇒uE​=−4.17cm=−4.2cm L=v0​+∣uE​∣=12.2cm here v0​=8cm f0​=+1cm⇒u0​=−1.1cm

$1.1 c m$

$2.2 c m$

$3.3 c m$

$4.4 c m$

For eyepiece, $V_{E} = - 25 c m, f_{E} = + 5 c m$
$\Rightarrow u_{E} = - 4.17 c m = - 4.2 c m$
$L = v_{0} + ∣ u_{E} ∣ = 12.2 c m$
here $v_{0} = 8 c m$
$f_{0} = + 1 c m \Rightarrow u_{0} = - 1.1 c m$