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 $1408c{{m}^{2}}$