6 (a) State what is meant by electric field strength. (b) An isolated metal sphere A of radius 26cm is positively charged. Sphere A is shown in Fig. 6.1. [Figure 6.1] Electrical breakdown (a spark) occurs when the electric field strength at the surface of the sphere exceeds 2.0 × 10⁴ Vm⁻¹. Calculate the maximum charge Q that can be stored on the sphere. Q = .............................................. C (c) A second isolated metal sphere B, also with charge +Q, has a radius of 52 cm. Calculate the additional charge, in terms of Q, that may be stored on this sphere before electrical breakdown occurs. additional charge = ..............................................

1. (a)State what is meant by electric field strength.[1]
2. (b)Calculate the maximum charge Q that can be stored on the sphere. Q = .............................................. C[2]
3. (c)Calculate the additional charge, in terms of Q, that may be stored on this sphere before electrical breakdown occurs. additional charge = ..............................................[2]

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