Hi! An object is placed 20 cm to the left of a converging lens of focal length 2

Question

Hi! An object is placed 20 cm to the left of a converging lens of focal length 25 cm. A diverging lens of focal length 10 cm is 25 cm to the right of the converging lens. Find the position and magnification of the final image. Okay,

converging

1/p + 1/q= 1/f

-1/20 + 1/q = 1/25

-1/20 - 1/25 = -1/q

-25/500 - 20/500 = -1/q

-45/500 = -1/q

500/45 = q = 11.11 cm

now the diverging lens

25 cm - 11.11cm = 13.89 cm

1/13.89 = 1/q = 1/-10

-1/13.89 + 1/10 = 1/q

-10/ 138.9 + 13.89/ 138.9 = -1/q

3.89/138.9 = -1q

-138.9/3.89 = q = 35.7

M = -q/p 35.7/13.89 = 2.5 WHICH ISN'T CORRECT, 9.30 cm in front of second lens M = 0.370 Anything

that would clear this up would help, Thanks!

Explanation / Answer

As far as I have seen your solution everything seems correct. All the signs and values have been properly put. I don't know why the answer is wrong but your solution and sign convention used are definitely right.. try recalculating the values.

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.