A right circular cylinder of radius \(r\) cm and height \(h\) cm (with \(h>2r\)) just encloses a sphere. The diameter of the sphere is
\(r\) cm
\(2r\) cm
\(h\) cm
\(2h\) cm
Step 1: A sphere is a perfectly round ball. If it is placed inside a cylinder, it will touch the cylinder from all sides.
Step 2: The widest part of the sphere is its diameter. This diameter must be the same as the inner width of the cylinder for the sphere to fit exactly.
Step 3: The inner width of the cylinder is measured across its circular base. That width is equal to the diameter of the base circle.
Step 4: The diameter of the base circle of the cylinder is \(2r\) (since radius is \(r\), diameter = \(2 \times r\)).
Step 5: Therefore, the diameter of the sphere = diameter of the cylinder’s base = \(2r\).
Final Answer: The diameter of the sphere is \(2r\) cm. (Option B)