Physics Help Forum Concave Mirror

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 Mar 20th 2017, 08:44 AM #1 Junior Member   Join Date: Feb 2017 Posts: 12 Concave Mirror Q.) A student has three concave mirrors A, B, C of focal lengths 20 cm, 15 cm and 10 cm respectively. Out of the three mirror identify the mirror which would be preferred to be used for shaving purpose.
 Mar 20th 2017, 10:22 AM #2 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 585 What do you think? When a mirror is used as a shaving mirror it is in virtual, magnifying mode. Therefore the object has to be between the focus and the mirror.
 Mar 20th 2017, 11:57 AM #3 Junior Member   Join Date: Feb 2017 Posts: 12 I agree. But I couldn't reach the answer still. Does it have something to do with least distance of distinct vision.
 Mar 20th 2017, 01:03 PM #4 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 585 How close to a mirror can you get and still operate a razor?
 Mar 20th 2017, 05:15 PM #5 Junior Member   Join Date: Feb 2017 Posts: 12 Mirrors of 15 or 20 cm focal length can be used as per my understanding.20 cm will be more apt.
Mar 20th 2017, 10:36 PM   #6
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 Originally Posted by Naazima I agree. But I couldn't reach the answer still. Does it have something to do with least distance of distinct vision.
?

Mar 30th 2017, 12:27 AM   #7
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 Originally Posted by Naazima Mirrors of 15 or 20 cm focal length can be used as per my understanding.20 cm will be more apt.
Please tell if the correct answer is 15 cm or 20 cm?

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