Question

his 245 Exam 3 Name Ellen places an doyed 40.6 cm from a concar en la vida image appears 10.0 cm from the lens on the same side as they was the focal length of the lens a. 50,0 cm b. -13,3 cm c.-10.0 cm d. -8.00 cm 14. If a wave from one sit of a Young's doublest set-up amies at a point on the screen one wavelength behind the weve from the others, what is observed at that point? a. dark fringe b. bright fringe c. multi-colored fringe d. grey fringe, neither dark nor bright 15. A Young's double slit has a separation of 2.50 x 10 m on which a monochromatic light beam is directed. The resultant bright fringes on a screen 1.00 m from the double slit are separated by 2.30 x 10 m. What is the wavelength of this beam? (1 nm = 10 m) a. 373 nm b. 454 nm C. 575 nm d. 667 nm Page 4

Answer 1

13.

Given
object =40
image =10
for virtual image
(1/object) - (1/image) = 1/f
(1/40) - (1/10) = 1/f
-3/40 = 1/f
f= -40/3 cm
f=-13.33cm
Option b is correct

where the negative shows the lens is diverging