Question

Assumimng new cartesian sign convention, choose the correct option for the Lens shown in figure:

• A. $R_1>0$
  $R_2>0$
• B. $R_1<0$
  $R_2<0$
• C. $R_1>0$
  $R_2<0$
• D. $R_1<0$
  $R_2>0$

Answer 1

The correct option is D $R_1<0$

$R_2>0$
According to the sign convention , all the distances measured in the direction of light rays are taken as positive, whereas all the distances measured in the direction of light rays are taken as negative.
In the given figure, rays are coming from left to right. Therefore,
$R_1<0$
$R_2>0$