A real object is 42.1 cm from a negative lens that has a focal length of 25.6 cm.The object is 2.45 mm high.The height and orientation of the image are
A)3.8 mm and inverted.
B)0.93 mm and erect.
C)6.4 mm and erect.
D)0.38 mm and erect.
E)None of these is correct.

Question

Quizplus · Accepted Answer

Using the lens formula 1/f = 1/do + 1/di, we can find the distance of the image from the lens as -16.56 cm (negative sign indicates an inverted image). Using the magnification formula M = -di/do = hi/ho, where hi and ho are the heights of the image and object respectively, we can find the height of the image as 0.93 mm (since M is negative, the image is also inverted). Therefore, the correct answer is B) 0.93 mm and erect, since the image is not only inverted but also smaller in size than the object, and appears on the same side of the lens as the object.

A Real Object Is 42