Question 1. Question on the masurment:

a) is the image enlarged or reduced when s > 2 f ? is the image enlarged or reduced when s < 2 f ?

b) is the image erect or inverted ? is the image real or virtual ? why?

Question 2.Explain why for a fixed separation between the object and the screen (i.e., s+ s' is fixed), there are two positions of the lens at which the image formed on the screen are in foucs (clear image).

Question 3. A lens forms an image of an object. the objet is 16 cm from the lens. The image is 12 cm from the lens on the same side as the object. 

(a) what is the focal length of the lens?? is the lens converging or diverging ?

(b) if the object is 8.5 mm tall, how tall is the image? is it erect or inverted?

(c) DRAW a principle-ray diagram.

Question 4: Hold the optics bench by your hand, look at the tree outside window using your telescope. is there image of the tree erect or inverted? is the image of the tree enlarged or reduced?

Question 5: The worlds largest refracting telescope is at the Yerkes Observation of the University od Chicago at Williams Bay, Wisconsin. the objective has diameter of 102 cm and focal length of 19.5 m. the focal length of the eyepiece is 10 cm. What is its magnification (or magnifying power)?