Consider two concentric spherical surface S1 with radius a and S2 with radius 2a, both centered on the origin….

Q: Consider two concentric spherical surface S1 with radius a and S2 with radius 2a, both centered on the origin. There is a charge +q at the origin, and no other charges. Compare the flux Φ₁ through S₁ with the flux Φ₂ through S₂

(a) Φ₁ = 4Φ₂

(b) Φ₁ = 2Φ₂

(c) Φ₁ = Φ₂

(d) Φ₁ = Φ₂/2

Ans:(c)

$ \phi = \frac{q}{\epsilon_0} $