gistfile1.txt

doc1 = {
  "_id" : 1,
  "p" : [ { "name" : "travis",
            "age"  : "21" },
          { "name" : "bob",
            "age"  : "21" } ] }

doc2 = {
  "_id" : 2,
  "p" : [ { "name" : "mark",
            "age"  : "21" },
          { "name" : "bob",
            "age"  : "32" } ] }

db.people.save(doc1)
db.people.save(doc2)


> db.people.find({ "p.name" : "bob", "p.age" : "21"})
{ "_id" : 1, "p" : [ { "name" : "travis", "age" : "21" }, { "name" : "bob", "age" : "21" } ] }
{ "_id" : 2, "p" : [ { "name" : "mark", "age" : "21" }, { "name" : "bob", "age" : "32" } ] }


> db.people.find({"p" : {"$elemMatch" : {"name" : "bob", "age" : "21"}}})
{ "_id" : 1, "p" : [ { "name" : "travis", "age" : "21" }, { "name" : "bob", "age" : "21" } ] }