Why does a fluid’s viscosity contribute to energy loss in real flow systems?
Viscosity causes internal friction between fluid layers, converting kinetic energy into heat through shear stress, leading to energy dissipation, which Bernoulli’s ideal flow neglects. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It converts kinetic energy to heat. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.