An isolated metal sphere of radius r is charged so that the electric field strength at its surface is E₀. On [Figure 6.1], sketch the variation of the electric field strength E with distance x from the centre of the sphere. Your sketch should extend from x = 0 to x = 3r.

1. (a)An isolated metal sphere of radius r is charged so that the electric field strength at its surface is E₀. On [Figure 6.1], sketch the variation of the electric field strength E with distance x from the centre of the sphere. Your sketch should extend from x = 0 to x = 3r.[3]
2. (b)The de Broglie wavelength of a particle is λ₀ when its momentum is p₀. On [Figure 6.2], sketch the variation with momentum p of the de Broglie wavelength λ of the particle for values of momentum from p₀/2 to p₀.[2]
3. (c)A radioactive isotope decays with a half-life of 15 s to form a stable product. A fresh sample of the radioactive isotope at time t = 0 contains N₀ nuclei and no nuclei of the stable product. On [Figure 6.3], sketch the variation with t of the number n of nuclei of the stable product for time t = 0 to time t = 45 s.[3]

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