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Solve this

Q. A convex lens of focal length 15 cm is placed in contact with a plane mirror and a candle is placed at the focal plane of the lens.

The image produced will be

(1) real and 15 cm in front of the mirror

(2) virtual and 15 cm in front of the mirror

(3) real and 30 cm in front of the mirror

(4) virtual and 30 cm in front of the mirror

Here in this case the equivalent focal length of the system when the convex lens is in contact with the plane mirror is ,

$\frac{1}{F}=\frac{1}{15}+\frac{1}{\infty}=\frac{1}{15}\phantom{\rule{0ex}{0ex}}\Rightarrow F=15cm\phantom{\rule{0ex}{0ex}}Nowasthecandleisplacedinthefocalplaneofthelensthen\phantom{\rule{0ex}{0ex}}theimagewillbeproducedat15cminfrontofthemirrorandtheimagewillbereal.$

So the correct option is 1 .

Regards

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