What is the right formula for a converging thin lens if the

What is the right formula for a converging thin lens if the image is real? 1/d_o + 1/d_i = 1/f 1/d_o + 1/d_i = 1/f 1/d_o - 1/d_i = 1/f -1/d_o + 1/d_i = 1/f During the lab experiment \"Current Balance\" why do we measure the current through the apparatus in both directions? To eliminate the effect of the electromotive force. To get more data for statistics. To compensate for the effect of gravitational force. To compensate for the effect of ambient magnetic field. To avoid uncertainties of the values of the current.

Solution

1. (1/object distance)+(1/image distance)=(1/focal length)

1/d_o + 1/d_i = 1/f

20. To compensate for the effect of gravitational force

In this lab, we balance a known gravitational force against the repulsive magnetic force between antiparallel currents. We use our results to calculate an experimental value for µ0, the permeability of free space. You may ignore errors for this lab.