Out of the following which law obeys the law of conservation of energy?

Lenz's law provides a direct application of energy conservation in electromagnetic induction. When magnetic flux through a circuit changes, the induced EMF generates a current whose magnetic field opposes the original flux change. This opposition prevents energy from being created or destroyed without external work.

$\mathcal{E} = -\frac{d\Phi_B}{dt}$

If the induced current reinforced rather than opposed the flux change, it would create a self-amplifying effect violating energy conservation. The negative sign in Faraday's law formulation embodies this energy conservation principle.

Kirchhoff's junction rule conserves charge, Ampere's law describes magnetostatics, and Gauss's law relates electric flux to charge—none directly express energy conservation.