Answer:
1.25 Nm²/C
Explanation:
Flux = quantity/(unit area)
Electric flux = Electric field/(unit area)
Let the initial area over which the flux is initially expressed be A
5 = Electric field/A
Electric field = 5A N/C
If this same electric field is expressed over an area double the initial diameter of the initial circle, the area of new circle = 4A.
This is because Area is proportional to the square of diameter. A = kD², so area of new circle with diameter 2D, A₁ = k(2D)² = 4kD² = 4A
New electric flux = 5A/4A = 5/4 = 1.25 Nm²/C