Answer:
option E
Explanation:
given,
diameter = 4 mm
shutter speed = 1/1000 s
diameter of aperture = ?
shutter speed = 1/250 s
exposure time to the shutter time
[tex]E V = log_2(\dfrac{N^2}{t})[/tex]
N is the diameter of the aperture and t is the time of exposure
now,
[tex]log_2(\dfrac{N^2}{t_1})=log_2(\dfrac{N^2}{t_2})[/tex]
[tex]\dfrac{N_1^2}{t_1}=\dfrac{N_2^2}{t_2}[/tex]
inserting all the values
[tex]\dfrac{4^2}{1000}=\dfrac{N_2^2}{250}[/tex]
N₂² = 4
N₂ = 2 mm
hence , the correct answer is option E
