We are getting 21cm because graph drawn is wrong. In y axis it goes as 10,20,30,.... and in x axis it goes as 26,28,30,.... The Scale is not proportional. So, If both x and y axis is taken as 10,20,30,.. Then we will get distances equal to 2f where bisector intersects on both x and y axis. So we will get f like this. (2f+2f)/4= 4f/4= f
lens should be kept in between F and 2F which was calculated approximately like in ur experiment it was 10 or lens beyond 2f plz tell mam if we keep in between F and 2F value r cming higher like urs was 10 but if we calculation 50+34/4 its cming 21 wht to do plz tell
