meteor client find is not working due to $eq - mongodb

Question

I subscribed to my servers's publication as follows:
Template.observedQuestions.onCreated(function(){
var self = this;
self.autorun(function(){
self.subscribe('observedQuestionsFeed');
});
});
Now I need to fetch my data using helper function:
Template.observedQuestions.helpers({
observedQuestionsList : function(){
questions = Questions.find({
observedByUsers : {$exists: true,$elemMatch:{$eq:Meteor.userId()}}});
return questions;
}
});
but it does not work due to $eq being not recognised in minimongo.
How to solve it?
doc sample:
{
"_id" : "rP4JP8jkprwwi3ZCp",
"qUserId" : "NLLW3RBXqnbSGuZ3n",
"type" : "question",
"date" : ISODate("2016-02-13T11:23:10.845Z"),
"subject" : "test",
"question" : "test",
"replies" : [
{
"rID" : "LphcqKnkTHf25SCwq",
"rUserID" : "NLLW3RBXqnbSGuZ3n",
"date" : ISODate("2016-02-13T11:23:10.847Z"),
"answer" : "reply1."
},
{
"rID" : "HxaohnEgxwNJLtf2z",
"rUserID" : "NLLW3RBXqnbSGuZ22",
"date" : ISODate("2016-02-13T11:23:10.848Z"),
"answer" : "reply2"
}
],
"observedByUsers" : [ "Bi24LGozvtihxFrNe" ]
}

Answer 1

Judging from your sample Questions document, the field observedByUsers is a simple array which contains user IDs.
As a result, you could simply use the following query:
Questions.find({observedByUsers: Meteor.userId()});