A Van De Graaff Generator Has a Spherical Dome of Radius

Multiple Choice

A Van de Graaff generator has a spherical dome of radius 12 cm.Operating in dry air,where "atmospheric breakdown" is at E_max = 3.0 × 10⁶ N/C,what is the maximum charge that can be held on the dome? (k_e = 8.99 × 10⁹ N⋅m²/C²)

A) 4.8 × 10−⁶ C
B) 1.3 × 10−⁵ C
C) 2.7 × 10−⁵ C
D) 3.3 × 10−⁶ C