(a)(i) State Coulomb's law of electrostatics.

(ii) The electron and proton of a hydrogen atom are separated by a mean distance of 5.2 x 10\(^{-11}\)m.

Calculate the magnitude of the electrostatic force between the particles.

[e = 1.6 x 10\(^{-19}\) C, (4\(\pi\) \(\mathcal{E}_{0}\))\(^{-1}\) = 9.0 x 10\(^{9}\) mF\(^{1}\)]

(b) The diagram above shows a potential divider circuit. (see diagram above)

i. Show that V\(_{out}\) = V\(_{in}\) (\(\frac{R_{1}}{R_{1} + R_{2}})\)

ii. If \(\frac{V_{in}}{V_{out}}\) = 2.5 and R\(_{2}\) = 30\(\Omega\), calculate R\(_{1}\)

iii. Define the volt.

(c) Explain why wood is not suitable for use as the core of transformers.

(d) State one application for the cathode ray tube.