Answer:
V = 72000 volts
Explanation:
calculates the electric potential of a point B that is 75cm from a positive charge q = 9 × 10-6c
Given that,
Electric charge, 
We need to find the electric potential of a point B that is 75 cm from this charge. The formula for the electric potential is given by :

So, the electric potential is equal to 72000 Volts.
Answer:
15mm
Explanation:
We know that for circular holes first dark spot is given by
sin စ = 1.22 λ/D
Also we know that at the same time
tan စ = r/L
So
r = L tanစ = 6 x tan( arcsin(1.22x 500 x10^9/0.50 x 10^ 3))
= 0.0073 m = 7.3 mm
However since the size is twice that so 14.6 mm which is approx 15mm
We know, d = m/v
d = 968 g/cm3
m = 250 gm
Substitute their values,
968 = 250 / v
v = 250 / 968
v = 0.26 cm3
In short, Your Answer would be Option B
Hope this helps!
Answer:
Look at this picture hopefully it helps