Opticks - 3

A plane mirror is placed 25cm away frm a spherical concave mirror (R=40cm) perpendicularly to the principal axis of the concave mirror.

Where is a candle placed, if its images formed by the two mirrors independently are at the same distance frm the candle ?
(Consider img(s) formed by single reflection only)

Mera answer nahi aa rahaa.....[186]

8 Answers

11
swaraj jena ·

iz the answer 10 cm from the concave mirror

13
Avik ·

Yep, the answer's 10....i want to see the working part, as to where am i going wrong...

11
swaraj jena ·

let it b at a distance x from the con mirror
so it will b at a distance 25-x from the pln mirror
so image formed by the the mirror will b at a distance 50-2x from the object
now the image formed by the mirror should b at same distance in any side
so if it will form the image where the image is formed by mirror then we hav image distance =50-x
if it will form image on the other side i.e opp to the mirror then image distance=50-3x for mirror
now put this data in mirror eqn using correct sign convension,u ll find that first one has no soln
but u ll get 10 by puting second one

13
Avik ·

Err... Lens kahaan se aa gaya..?

11
swaraj jena ·

sorry,i hav written lens in place of mirror ,but solved using mirror formulas.i hav edited my mistakes

13
Avik ·

Lekin Yeh kaise aaya..... so it will b at a distance 5-x from the mirror ??

13
Avik ·

k...tht shud be (25-x)...koi gal nahi,,, i did not take the 2nd case only :P

Thnx [1].

11
swaraj jena ·

wel com

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