For the classical ideal gas which of the following is correct.
1
\(\left(\frac{\partial U}{\partial V}\right)_T=0\)
2
\(\left(\frac{\partial U}{\partial T}\right)_V=0\)
3
\(\left(\frac{\partial T}{\partial V}\right)_P=0\)
4
\(\left(\frac{\partial P}{\partial V}\right)_T=0\)