A good engineer will create an outline that meets the useful necessities of the venture and after that play out an anxiety examination to get certainty that the tower will be sheltered under the normal scope of working conditions. By then, the outline will be tastefully satisfying to engineers. On the off chance that the customer needs something all the more stylishly cleaned, he may need to utilize a plan authority. A designer who puts feel initially is taking a chance with his expert standing.
I believe the answer is C
8.6 cm
Explanation:
Step 1:
In this we have to find the focal length of converging lens.
To find focal length we have,

where u = Object distance
v= Image distance
f = Focal length
Step 2:

(1/f) = 0.116
f = 1/0.116
f = 8.6 cm
Answer:
2.316e-3 and 3.47e-3
Explanation:
Now, at that angle, we look at the bright spots on the screen.
tan θ = x / L (x is the horizontal distance from the centre of the screen, L is distance to screen)
For small angles, we can approximate that tan θ = sin θ.
nλ / d = x / L so then
x = n λ L / d
First bright fringe, n = 1
x = (1) (641*10^-9 m) (3.65 m) / (1.01*10^-3 m) = 2.316e-3
For destructive interference (dark fringes), equation becomes:
x = (n - 0.5) λ L / d
Second dark fringe, n = 1.5
x = 1.5 (641*10^-9 m) (3.65 m) / (1.01*10^-3 m) = 3.47e-3