A convex lens of focal length 100 , cm and a | vedclass

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(C) $1$. When a parallel beam of light is incident on a convex lens of focal length $f_1 = 100 \, cm$,it converges towards its focus,which is at a dis

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Remains parallel

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(C) $1$. When a parallel beam of light is incident on a convex lens of focal length $f_1 = 100 \, cm$,it converges towards its focus,which is at a distance of $100 \, cm$ from the convex lens.$2$. The concave lens is placed at a distance of $90 \, cm$ from the convex lens. Therefore,the light rays are directed towards a point $10 \, cm$ behind the concave lens.$3$. For the concave lens,this point acts as a virtual object. The distance of this virtual object from the concave lens is $u = +10 \, cm$.$4$. The focal length of the concave lens is $f_2 = -10 \, cm$.$5$. Using the lens formula $\frac{1}{v} - \frac{1}{u} = \frac{1}{f}$,we get $\frac{1}{v} - \frac{1}{10} = \frac{1}{-10}$.$6$. This simplifies to $\frac{1}{v} = 0$,which means $v = \infty$.$7$. Since the image is formed at infinity,the light rays emerge from the concave lens as a parallel beam.

$A$ convex lens of focal length $100 \, cm$ and a concave lens of focal length $10 \, cm$ are placed coaxially at a separation of $90 \, cm$. If a parallel beam of light is incident on the convex lens,then after passing through the two lenses,the beam:

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