MongoDB Associate Practice Test

1. Which data format does MongoDB use to store documents?

JSON

BSON

XML

CSV

2. In MongoDB, what is the primary key field called?

Primary_id

_id

Key_id

Doc_id

3. Which operator is used to find documents where a field value is greater than a specified value?

$gt

$gte

$gtr

$greater

4. What does the $match stage do in an aggregation pipeline?

Joins two collections

Filters documents based on criteria

Groups documents by field

Sorts documents in order

5. Which index type in MongoDB improves query performance on a single field?

Compound index

Geospatial index

Single field index

Text index

6. In MongoDB, what does the $project stage do in aggregation?

Limits the number of documents

Selects and reshapes fields in documents

Removes duplicate documents

Counts total documents

7. Which command creates a new index on a collection?

Db.collection.createIndex()

Db.collection.addIndex()

Db.collection.newIndex()

Db.collection.makeIndex()

8. What is the purpose of the $group stage in aggregation?

Filter unwanted documents

Group documents by a field and perform calculations

Sort documents alphabetically

Limit output to N documents

9. Which operator allows you to match documents where a field equals any value in an array?

$in

$all

$elem

$match

Submit

11. What does the $lookup stage do in an aggregation pipeline?

Performs a join with another collection

Filters documents by regex

Limits the number of results

Converts field data types

12. Which method removes a single document from a collection?

DeleteOne()

RemoveOne()

DropOne()

DeleteDocument()

Submit

14. Which of the following is a valid MongoDB data type?

Integer

Array

Object

All of the above

15. In MongoDB, what is the maximum size of a single document?

4 MB

8 MB

16 MB

32 MB