Test: Types of Flow Lines - Mechanical Engineering MCQ

Explanation: A pathline is the path followed by a particle in motion. For an one-dimensional flow, the fluids move in only one dimension (say x). Hence the pathline will also be a straight line (along that direction).

Explanation: The pathline of a particle in an one-dimensional flow is a straight line along the direction it moves. If the two particles move along the same direction, their pathlines will be parallel to each other and will never intersect.

Explanation: The pathline of a particle in an one-dimensional flow is a straight line along the direction it moves. When two particles move in the same direction, their pathline will never intersect and when they move in different directions, their pathlines will intersect only once.

Explanation: A pathline is the path followed by a particle in motion whereas a streamline is an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point.

Explanation: A streamline is defined as an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. At a point, there can only be one direction of velocity. Hence, neither can a streamline intersect itself nor can two streamlines cross each other.

Explanation: A streamline is defined as an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. In a steady flow, the velocity of the particles is constant with time. Hence, the streamlines remain the same even after sometime.

Explanation: Streamline spacing varies inversely as the velocity. In a uniform flow, the velocities of the particles are the same at every instant of time. Hence, the spacing between their streamlines will be the same. In other words, the streamlines will be parallel.

Explanation: A streamline is defined as an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. Flow can only be along the velocity, never perpendicular to it. Hence, the movement of fluid mass can only be along the streamlines and never across them.

Explanation: A pathline is the path followed by a particle in motion whereas a streamline is an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. Thus, pathlines are concerned with a particular particle at successive instants of time and streamlines with a number of particles at the same instant.

Explanation: A pathline is the path followed by a particle in motion whereas a streamline is an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. A streamtube is a collection of streamlines. A streakline is a curve which gives an instantaneous picture of the location of the fluid particleswhich have passed through a given point.
Hence, the path taken by the smoke coming out of a chimney (in concentric circles) will represent streaklines.