d through a railroad track
Answer:
usually x-ray tube filaments are devices that limit the current flow i.e. current cannot easily pass through them or we can say that they are current limited devices. So to allow fine electron transmission control by filament heating current, rhenium must not be used in x-ray tube filaments.
Answer:
The upward buoyancy force on an object acts through the overall center of buoyancy, being the centroid of the displaced volume of fluid. The weight force on the object acts through its center of gravity.