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प्रश्न
If two solid-hemisphere s of same base radius r are joined together along their bases , then curved surface area of this new solid is
विकल्प
\[4 \pi r^2\]
\[6 \pi r^2\]
\[3 \pi r^2\]
\[8 \pi r^2\]
उत्तर
Base radius of the hemisphere = r
Since the two hemispheres are joined end to end, it becomes a complete sphere.
Curved surface area of the new solid = total surface area of the sphere.
\[\text { Curved surface area of the new solid } = 4 \pi r^2\]
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