Answer : The main reason for generation of harmonics in a transformer could be saturation of core.
Description : Purpose of Selective Catalytic Reduction (SCR)
Answer : Purpose of Selective Catalytic Reduction (SCR) : 1. It reduces Nox 75% to 90% 2. Converts it in to molecular nitrogen and water vapor 3. It reduces HC emission up to 80% 4. It reduces PM emission 20 to 25%.
Answer : When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding. Thus sliding is acute when wheel base of axles is more, degree of curvature is more.
Description : Reduction in core losses and increase in permeability are obtained with transformer employing?
Answer : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.
Description : Explain the effect of Harmonics on the Transformer.
Answer : Effect of Harmonics on the Transformer: 1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations. 5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.