Two Lenses, One with a Focal Length F₁ = +20

question 52

Multiple Choice

Two lenses, one with a focal length f₁ = +20 cm and the other with a focal length f₂ = -20 cm, are on the same axis and 60 cm apart as shown. A real object is 40 cm to the left of the first lens, as shown. The final image formed by this two-lens combination is

• A) real and 10 cm from the negative lens.
• B) virtual and 10 cm from the negative lens.
• C) at infinity.
• D) virtual and 20 cm from the negative lens.
• E) None of these is correct.