Question

A clear glass light bulb is placed 0.750 m from a convex lens having a 0.50 m focal length, as shown in Figure c. Use the thin lens equations to calculate the location of the image (d; or i) and its magnification (M). Light bub Screen f = 0,50 m di = ? FR de=0.75 in Hint: Use the definitions shown in the picture below.

Answer 1

(1) object distance do = 0.75 m;

focal length f = 0.5 m;

thin lens equation;

$\frac{1}{f}=\frac{1}{d_o}+\frac{1}{d_i}$

$\frac{1}{0.5}=\frac{1}{0.75}+\frac{1}{d_i}$

Image distance;

since image distance is poitive, thus image formed on right side of lens.

Magnification;

$M=-\frac{d_i}{d_0}=-\frac{1.5}{0.75}$

$M=-2$

since magnification is negative, thus image is inverted.

Conclusion:

for convex lens: if object is placed in between F and 2F, then real, inverted and enlarged image is formed on the right side of the lens.