Sample code:


Lightning Component:


<aura:component >
<ui:inputRadio text=”Sample1″ label=”Sample 1″ name=”Role” change=”{!c.onGroup}”/><br/>
    <ui:inputRadio text=”Sample2″ label=”Sample 2″ name=”Role” change=”{!c.onGroup}”/><br/>
    <ui:inputRadio text=”Sample3″ label=”Sample 3″ name=”Role” change=”{!c.onGroup}”/><br/>
    <ui:inputRadio text=”Sample4″ label=”Sample 4″ name=”Role” change=”{!c.onGroup}”/><br/>
    <ui:inputRadio text=”Sample5″ label=”Sample 5″ name=”Role” change=”{!c.onGroup}”/>

</aura:component>


Lightning Controller:


({
    onGroup: function(cmp, evt) {
        var selected = evt.getSource().get(“v.text”);
        alert(selected);
    }

})


Output: