According to the question,
50 circular plates each with diameter $14cm$
Radius of circular plates $=7cm$
Thickness of plates $=0.5cm$
We have to find the total surface area
As these plates is one above the other, the total thickness of all the plates $0.5\times 50=25cm$
Now, the total surface area of the right circular cylinder formed $=2\pi r\times h+2\pi {{r}^{2}}$
$=2\pi r\left( h+r \right)$
$=2\left( 22/7 \right)\times 7\times \left( 25+7 \right)$
$=2\times 22\times 32=1408c{{m}^{2}}$
Hence, the total surface area of the cylinder is $1408c{{m}^{2}}$