. State the sign convention to measure the distances for a lens


State the sign convention to measure the distances for a lens.

 

Best Answer

The axis along which the distances are measured is called as the principal axis. These distances are measured from the optical centre of the lens.

The distances measured in the same direction as that of incident light are taken as positive

The distances measured against the direction of incident light are taken as negative

The distances measured upward and perpendicular to the principal axis are taken as positive

The distances measured downwards and perpendicular to principal axis is taken as negative

The focal length of the convex lens is taken as positive and that of concave lens is taken as negative

 

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