ANS:C - steady uniform flow.

One-dimensional fluid flow implies the flow in which transverse components are zero.

Explanation:

1. Definition of One-Dimensional Flow:
   • One-dimensional flow refers to fluid motion where the velocity components in directions perpendicular to the primary flow direction are negligible or zero.
   • It is a simplification used in fluid dynamics to analyze and understand fluid behavior in straight channels or pipes where variations across the cross-section are minimal.
2. Characteristics of One-Dimensional Flow:
   • Transverse Components: In one-dimensional flow, the velocity components in the directions perpendicular to the main flow direction are assumed to be zero or negligible.
   • This assumption allows for simpler calculations and analysis because it reduces the Navier-Stokes equations to one-dimensional forms or can be approximated using simpler equations like Bernoulli's equation.
3. Options Analysis:
   • Flow in straight lines only: This is not necessarily true as one-dimensional flow can occur in curved channels or pipes as long as the transverse velocity components are small.
   • Uniform flow: Uniform flow implies constant velocity across the entire cross-section, which is not necessarily the case for one-dimensional flow.
   • Steady uniform flow: While one-dimensional flow can be steady (time-independent), it does not imply uniform velocity across the cross-section.
   • Flow in which transverse components are zero: This correctly describes one-dimensional flow, where the flow is considered to occur primarily in one direction with negligible transverse components.

Conclusion:

Therefore, one-dimensional fluid flow implies the flow in which transverse components are zero, meaning the velocity components perpendicular to the primary flow direction are either zero or negligible. This condition simplifies fluid dynamics analysis and is applicable in scenarios where variations across the cross-section are minimal.