Question

The figure shows a combination of two identical lenses.

Find the position of the final image of the 2.0-cm-tall object. Express your answer using two significant figures. x=_______cm from the object. Find the size of the final image of the 2.0-cm-tall object. Express your answer using two significant figures.

h=

Find the orientation of the final image of the 2.0-cm-tall object.

	erect
	inverted

Answer 1

A)image due to 1st lense is

1/di = 1/f - 1/do =1/9 - 1/36 => di = 12cm

So for second lense object is at 15-12 cm = 3 cm away

So 1/di = 1/9 - 1/3 = -4.5 cm

So distance from object is 36 + 15 - 4.5 = 46.5 cm Answer

B) Magnification1 = -di/do

=> height after 1st lense = -2*12/36 = -0.667 cm

height after second lense = -0.666*4.5/3 = -0.99 cm Answer

c) inverted because height is -ve Answer