Will a capacitor of 10uf 250v work as good as a cap 10uf 50v?
Yes - the voltage rating is an indication of the maximum the capacitor can be subjected to. Above that voltage the insulation (dielectric) layer breaks down and the device is destroyed.

The capacity (50uF) is the same and from a circuit point of view that's the important factor. 

However, there may be other factors such as leakage current and inductance that will vary from capacitor type to capacitor type. These may become the reason for choosing one type of capacitor against another of the same value in a particular circuit.