In transformers, power conservation is ensured due to the absence of significant energy losses. The ideal transformer, with 100% efficiency, has a power input equal to its output power. This is achieved through the efficient transfer of magnetic energy from the primary to the secondary winding, minimizing losses due to resistance, hysteresis, and eddy currents. The magnetic coupling between windings ensures that the power drawn from the source is transferred to the load without significant dissipation.