fixed field width of panelFormLayout child Components

solution link
http://www.jobinesh.com/2011/02/customizing-width-of-ui-control-using.html
extra knoledge link
http://docs.oracle.com/cd/E23943_01/web.1111/b31973/af_orgpage.htm#CACCBCCI
solution
You can use contentStyle attribute to override the default width of specific types of UI controls. This property is applicable for single select and multiple select controls( af:selectOneChoice, af:selectManyShuttle, af:selectBooleanRadio etc.) and input controls( af:inputText, af:inputRangeSlider, af:inputListOfValues,af:richTextEditor etc. ). 

<af:selectOneChoice  contentStyle="width:200px" label="Select an Item:" id="soc1">