Question

trial	xo	xi	xL	do	ho	di	hi	m=hi/ho	di/do
1	0.1	1.1	0.2145	0.1145	0.01	0.8855	0.076	7.6	7.733624
2	0.1	1	0.2125	0.1125	0.01	0.7875	0.066	6.6	7
3	0.1	0.9	0.22	0.12	0.01	0.68	0.056	5.6	5.666667
4	0.1	0.8	0.224	0.124	0.01	0.576	0.046	4.6	4.645161
5	0.1	0.7	0.228	0.128	0.01	0.472	0.036	3.6	3.6875
6	0.1	0.6	0.24	0.14	0.01	0.36	0.026	2.6	2.571429

Hello! I am confused about where I went wrong or if I did make a mistake, why di/do > 0 and hi/ho >0 ? since m = hi/ho = -di/do these values do not agree

above is my experimental data

an optical rail was used and an object was placed at xo = 0.1m. The image was projected onto a screen and the location of the image/screen xi was changed each trial. The lens was placed at xL and adjusted at each trial to produce a clear image. all values are in meters, a convex lens was used.

do = xL - xo , di = xi - xL

maybe do should be do = xo - xL , but then the calculations for focal length f do not make sense if substituted into 1/f = 1/di + 1/do (f = 100mm)

The image produced was larger than the object, therefore M > 0.

Please help!!! Im very confused about the positive / negatives

sorry so much data i wanted to include all relevant information

Answer 1

I think you are using a convex lens. Since the image is being formed on the screen, which means that the image is real. A real image formed by a convex lens is always inverted. Therefore, clearly you should have

. Therefore, magnification is negative, which is expected because the image is inverted. Let me see if it clarifies.