A parallel beam of light is incident on the system of two convex lenses of focal lengths $f_{1} = 20 c m$ and $f_{2} = 10 c m$ . What should be the distance between the two lenses so that rays after refraction from both the lenses pass undeviated.

Question

A parallel beam of light is incident on the system of two convex lenses of focal lengths

f_{1} = 20 c m

and

f_{2} = 10 c m

. What should be the distance between the two lenses so that rays after refraction from both the lenses pass undeviated.

Toppr Admin · Accepted Answer

For the rays to pass undeviated- the image formed by the first lens should lie at the focus of the second lens-The first image is formed at a distance 20 cm from the first lens- and the second lens should lie at 10 cm from this point- So- the total distance - 20 -10 - 30

A parallel beam of light is incident on the system of two convex lenses of focal lengths $f_{1} = 20 c m$ and $f_{2} = 10 c m$ . What should be the distance between the two lenses so that rays after refraction from both the lenses pass undeviated.
$60 c m$
$30 c m$
$40 c m$
$90 c m$

For the rays to pass undeviated, the image formed by the first lens should lie at the focus of the second lens.
The first image is formed at a distance 20 cm from the first lens. and the second lens should lie at 10 cm from this point. So, the total distance = 20 +10 = 30

A parallel beam of light is incident on the system of two convex lenses of focal lengths f1=20 cm and f2=10 cm. What should be the distance between the two lenses so that rays after refraction from both the lenses pass undeviated.60cm30cm40cm90cm

For the rays to pass undeviated, the image formed by the first lens should lie at the focus of the second lens.The first image is formed at a distance 20 cm from the first lens. and the second lens should lie at 10 cm from this point. So, the total distance = 20 +10 = 30

A parallel beam of light is incident on the system of two convex lenses of focal lengths $f_{1} = 20 c m$ and $f_{2} = 10 c m$ . What should be the distance between the two lenses so that rays after refraction from both the lenses pass undeviated.
$60 c m$
$30 c m$
$40 c m$
$90 c m$

For the rays to pass undeviated, the image formed by the first lens should lie at the focus of the second lens.
The first image is formed at a distance 20 cm from the first lens. and the second lens should lie at 10 cm from this point. So, the total distance = 20 +10 = 30