CBSE Class 10 Answered
In case of mirror , distances are measured from pole of the mirror .
Distance from pole to a point left of mirror is considered as negative distance .
Distance from pole to a point right of mirror is considered as positive distance .
Hence if object is left side of mirror , then the distance from mirror to object is negative.
If object is right side of mirror , then the distance from mirror to object is positive.
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In case of lens , distances are measured from optical centre of the lens .
Distance from optical centre to a point left of lens is considered as negative distance .
Distance from optical center to a point right of lens is considered as positive distance .
Hence if object is left side of lens , then the distance from lens to object is negative.
If object is right side of lens , then the distance from lens to object is positive.
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