Hemisphere and its surface area

Q. The total surface area of a hemisphere having radius r is _____ .

1. $4\pi r^2$
2. $3\pi r^2$
3. $2\pi r^2$
4. $\frac{5}{2}\left(\pi r^2\right)$

Q.

I take a flat metallic circular plate of radius r. Now by hammering it I now convert it into a metallic hemisphere of same radius as circular plate. What is the change in surface area of the metal due to the hammering?

1. 2πr²

2. 3πr²

3. 4πr²

4. πr²