Ray Optics

JEE Main level, single correct, medium

288 of 295

Question 288 of 295

The focal lengths of objective lens and eye lens of a Galilean Telescope are respectively 30 cm and 3.0 cm. Telescope produces virtual, erect image of an object situated far away from it at least distance of distinct vision from the eye lens. In this condition the Magnifying Power of the Galilean Telescope should be :

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Answer: (C) +11.2+11.2

MP=−f⁡0f⁡e(1+f⁡eD)\text{MP}=\dfrac{-{f⁡}_{0}}{{f⁡}_{\text{e}}}\left(1+\dfrac{{f⁡}_{\text{e}}}{\text{D}}\right)

=−30−3(1+∣−3∣25)=\dfrac{-30}{-3}\left(1+\dfrac{\left|-3\right|}{25}\right)

=+11.2=+\text{11.2}

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