A 35 mm film is to be projected on a 20 m wide screen situated at a di – McqOptions

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1.	A 35 mm film is to be projected on a 20 m wide screen situated at a distance of 40 m from the film-projector. Calculate the focal length of projection lens.
A.	70 mm
B.	35 mm
C.	40 mm
D.	20 mm
Answer» B. 35 mm

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