Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
In some SVG attributes width and height absent. For this files you need specify -size manually. And you cannot determine size with imagemagick.
If you have empty result try other, bigger size.