Write the mathematical form of Snell's law

Write the mathematical form of Faraday's law of electromagnetic induction.

The mathematical form of the first law of thermodynamics when heat(q) is supplied and W is work done by the system(+ve) is:

Write the vector form of Coulomb's law in S.I system.

What is mathematical form of energy density?

State Gauss.s law of electrostatics and write down its mathematical form with identification of the symbols. Derive Coulomb.s law from Gauss.s law.