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mongodb MCQ Mock Test

80 Questions • 20 Seconds / Question

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Q 1/80

mongodb MCQs with Answers

1. TTL index is used for?

A. Expire documents
B. Sort documents
C. Join collections
D. Validate schema

Correct: A

Explanation: TTL index expires docs.

2. Authentication mechanism?

A. User-password
B. OAuth
C. Kerberos
D. All of the above

Correct: D

Explanation: MongoDB supports multiple auth.

3. Covered query means?

A. Uses index only
B. Uses collection scan
C. Uses aggregation
D. Uses join

Correct: A

Explanation: Covered query uses index only.

4. Primary node role?

A. Read only
B. Write operations
C. Backup only
D. Analytics

Correct: B

Explanation: Primary handles writes.

5. Transactions require?

A. Replica set
B. Standalone
C. Single node
D. Index

Correct: A

Explanation: Transactions need replica set.

6. Which operator removes array element?

A. $pop
B. $pull
C. $remove
D. $delete

Correct: B

Explanation: $pull removes element.

7. Secondary node role?

A. Writes
B. Reads and replication
C. Delete
D. Indexing

Correct: B

Explanation: Secondary replicates data.

8. Which index enforces uniqueness?

A. Normal index
B. Unique index
C. Text index
D. Sparse index

Correct: B

Explanation: Unique index enforces uniqueness.

9. NoSQL means?

A. No Structure
B. Not Only SQL
C. Non Secure
D. No Storage

Correct: B

Explanation: NoSQL = Not Only SQL.

10. Which stage skips documents?

A. $skip
B. $ignore
C. $offset
D. $pass

Correct: A

Explanation: $skip skips documents.

11. Which field uniquely identifies a document?

A. id
B. _id
C. docId
D. primaryId

Correct: B

Explanation: _id uniquely identifies document.

12. MongoDB supports transactions?

A. No
B. Yes, multi-document
C. Only single document
D. Only sharded

Correct: B

Explanation: MongoDB supports multi-document transactions.

13. Which operator matches values greater than?

A. $gt
B. $lt
C. $eq
D. $ne

Correct: A

Explanation: $gt means greater than.

14. Which operator pushes element to array?

A. $add
B. $push
C. $append
D. $insert

Correct: B

Explanation: $push adds element.

15. Which language is MongoDB written in?

A. Java
B. Python
C. C++
D. Go

Correct: C

Explanation: MongoDB is written in C++.

16. ObjectId contains?

A. Timestamp
B. Machine id
C. Process id
D. All of the above

Correct: D

Explanation: ObjectId contains multiple fields.

17. Default storage engine?

A. MMAPv1
B. WiredTiger
C. InMemory
D. RocksDB

Correct: B

Explanation: WiredTiger is default.

18. Which tool validates schema?

A. JSON Schema
B. XML Schema
C. BSON Schema
D. SQL Schema

Correct: A

Explanation: JSON Schema validates schema.

19. Which stage limits results?

A. $limit
B. $restrict
C. $slice
D. $cap

Correct: A

Explanation: $limit limits documents.

20. What type of database is MongoDB?

A. Relational
B. Document-oriented
C. Graph
D. Key-value

Correct: B

Explanation: MongoDB is a document-oriented NoSQL database.

21. MongoDB document is similar to?

A. Row
B. Column
C. Table
D. Index

Correct: A

Explanation: Document is similar to row.

22. Replication provides?

A. Backup
B. High availability
C. Scaling
D. Security

Correct: B

Explanation: Replication provides availability.

23. MongoDB stores data in which format?

A. XML
B. CSV
C. JSON
D. BSON

Correct: D

Explanation: MongoDB stores data in BSON format.

24. Best practice for schema?

A. Large documents
B. Embed frequently accessed data
C. Normalize everything
D. No indexes

Correct: B

Explanation: Embedding improves performance.

25. Explain() shows?

A. Query plan
B. Execution stats
C. Indexes used
D. All of the above

Correct: D

Explanation: Explain shows details.

26. Election occurs when?

A. Primary fails
B. Secondary fails
C. Client fails
D. Index fails

Correct: A

Explanation: Election occurs on primary failure.

27. TTL index works on?

A. Date field
B. String field
C. Number field
D. Object field

Correct: A

Explanation: TTL works on Date.

28. Which operator checks equality?

A. $eq
B. $same
C. $is
D. $match

Correct: A

Explanation: $eq checks equality.

29. MongoDB supports ACID?

A. No
B. Only single document
C. Multi-document
D. Only sharded

Correct: C

Explanation: MongoDB supports ACID transactions.

30. MongoDB is?

A. SQL
B. NoSQL
C. GraphQL
D. NewSQL

Correct: B

Explanation: MongoDB is NoSQL.

31. MongoDB favors?

A. CP
B. AP
C. CA
D. None

Correct: B

Explanation: MongoDB favors AP.

32. Text index is used for?

A. Numbers
B. Geolocation
C. Full-text search
D. Sorting

Correct: C

Explanation: Text index supports search.

33. Sharding provides?

A. Security
B. Replication
C. Horizontal scaling
D. Backup

Correct: C

Explanation: Sharding scales horizontally.

34. Which query is slow?

A. Index scan
B. Covered query
C. Collection scan
D. Shard query

Correct: C

Explanation: Collection scan is slow.

35. Which stage sorts documents?

A. $sort
B. $order
C. $arrange
D. $rank

Correct: A

Explanation: $sort sorts documents.

36. CAP theorem stands for?

A. Consistency Availability Partition
B. Consistency Access Performance
C. Cache Availability Partition
D. None

Correct: A

Explanation: CAP theorem definition.

37. Which command shows all databases?

A. show db
B. show databases
C. show dbs
D. list dbs

Correct: C

Explanation: show dbs lists databases.

38. Which is valid MongoDB type?

A. ObjectId
B. UUID
C. Char
D. BinaryString

Correct: A

Explanation: ObjectId is MongoDB type.

39. Which command inserts a document?

A. insert()
B. insertOne()
C. add()
D. push()

Correct: B

Explanation: insertOne inserts document.

40. Which operator matches less than?

A. $lt
B. $gt
C. $lte
D. $ne

Correct: A

Explanation: $lt means less than.

41. GUI tool for MongoDB?

A. Compass
B. Workbench
C. Studio
D. Manager

Correct: A

Explanation: Compass is MongoDB GUI.

42. Which command deletes documents?

A. removeOne()
B. deleteOne()
C. delete()
D. dropOne()

Correct: B

Explanation: deleteOne removes document.

43. Document size limit?

A. 8MB
B. 16MB
C. 32MB
D. Unlimited

Correct: B

Explanation: Document limit is 16MB.

44. Which command updates documents?

A. modify()
B. change()
C. updateOne()
D. edit()

Correct: C

Explanation: updateOne updates document.

45. Oplog stores?

A. Queries
B. Operations
C. Indexes
D. Backups

Correct: B

Explanation: Oplog stores operations.

46. ACID stands for?

A. Atomicity Consistency Isolation Durability
B. Access Control Isolation Data
C. Auto Commit Isolation Data
D. None

Correct: A

Explanation: ACID defines transactions.

47. Which command finds documents?

A. search()
B. select()
C. find()
D. get()

Correct: C

Explanation: find() retrieves documents.

48. Authorization controls?

A. Access rights
B. Performance
C. Replication
D. Indexing

Correct: A

Explanation: Authorization controls access.

49. Which operator calculates sum?

A. $sum
B. $add
C. $total
D. $plus

Correct: A

Explanation: $sum calculates sum.

50. $facet is used for?

A. Multiple pipelines
B. Filtering
C. Sorting
D. Joining

Correct: A

Explanation: $facet runs multiple pipelines.

51. Shard key is?

A. Index
B. Partition key
C. Primary key
D. Foreign key

Correct: B

Explanation: Shard key partitions data.

52. Which operator matches array value?

A. $in
B. $all
C. $elemMatch
D. All of the above

Correct: D

Explanation: All operators match arrays.

53. $lookup works with?

A. Same collection
B. Multiple collections
C. Only arrays
D. Indexes only

Correct: B

Explanation: $lookup joins collections.

54. Which role has full access?

A. read
B. readWrite
C. dbOwner
D. admin

Correct: D

Explanation: admin has full access.

55. Which command selects a database?

A. use db
B. use database
C. switch db
D. select db

Correct: A

Explanation: use db selects database.

56. Oplog is?

A. Capped collection
B. Normal collection
C. View
D. Index

Correct: A

Explanation: Oplog is capped.

57. Backup tool?

A. mongodump
B. mongobackup
C. mongosave
D. dumpdb

Correct: A

Explanation: mongodump creates backup.

58. Default port of MongoDB?

A. 27017
B. 3306
C. 5432
D. 8080

Correct: A

Explanation: MongoDB runs on port 27017.

59. Which operator sets a field value?

A. $set
B. $push
C. $inc
D. $add

Correct: A

Explanation: $set sets field value.

60. $elemMatch is used for?

A. Matching elements
B. Matching documents
C. Joining collections
D. Sorting

Correct: A

Explanation: $elemMatch matches array elements.

61. deleteMany removes?

A. One document
B. Multiple documents
C. Database
D. Index

Correct: B

Explanation: deleteMany removes multiple.

62. MongoDB schema is?

A. Fixed
B. Strict
C. Flexible
D. Required

Correct: C

Explanation: MongoDB schema is flexible.

63. What is an index?

A. Collection
B. Document
C. Performance structure
D. Constraint

Correct: C

Explanation: Indexes improve query performance.

64. MongoDB collection is similar to?

A. Table
B. Row
C. Column
D. Index

Correct: A

Explanation: Collection is similar to table.

65. Which operator increments value?

A. $inc
B. $set
C. $mul
D. $sum

Correct: A

Explanation: $inc increments value.

66. Poor shard key causes?

A. Data imbalance
B. Fast queries
C. Low latency
D. Security risk

Correct: A

Explanation: Poor shard key causes imbalance.

67. Restore tool?

A. mongorestore
B. mongoload
C. mongorecover
D. dbrestore

Correct: A

Explanation: mongorestore restores data.

68. Aggregation pipeline stage to filter?

A. $filter
B. $match
C. $where
D. $find

Correct: B

Explanation: $match filters documents.

69. Atlas provides?

A. Hosting
B. Monitoring
C. Scaling
D. All of the above

Correct: D

Explanation: Atlas provides full service.

70. Which improves performance?

A. Indexes
B. Large documents
C. Unbounded arrays
D. Joins

Correct: A

Explanation: Indexes improve performance.

71. $project is used for?

A. Include/exclude fields
B. Sort
C. Group
D. Join

Correct: A

Explanation: $project controls fields.

72. WiredTiger is?

A. Query engine
B. Storage engine
C. Index engine
D. Network layer

Correct: B

Explanation: WiredTiger is storage engine.

73. Which node becomes primary?

A. Random
B. Highest priority
C. Oldest
D. Fastest

Correct: B

Explanation: Highest priority becomes primary.

74. Which command creates index?

A. createIndex()
B. addIndex()
C. makeIndex()
D. index()

Correct: A

Explanation: createIndex creates index.

75. $unwind does?

A. Flattens arrays
B. Groups data
C. Sums values
D. Filters

Correct: A

Explanation: $unwind flattens arrays.

76. Which stage groups documents?

A. $group
B. $sum
C. $avg
D. $collect

Correct: A

Explanation: $group groups documents.

77. Compass is used for?

A. Querying
B. Indexing
C. Visualization
D. All of the above

Correct: D

Explanation: Compass supports all.

78. updateMany updates?

A. One document
B. Multiple documents
C. Collection
D. Database

Correct: B

Explanation: updateMany updates multiple.

79. MongoDB joins using?

A. $join
B. $lookup
C. $merge
D. $union

Correct: B

Explanation: $lookup performs joins.

80. MongoDB Atlas is?

A. CLI tool
B. Cloud database
C. Backup tool
D. GUI client

Correct: B

Explanation: Atlas is cloud MongoDB.

mongodb MCQ Mock Test

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mongodb MCQs with Answers

1. TTL index is used for?

2. Authentication mechanism?

3. Covered query means?

4. Primary node role?

5. Transactions require?

6. Which operator removes array element?

7. Secondary node role?

8. Which index enforces uniqueness?

9. NoSQL means?

10. Which stage skips documents?

11. Which field uniquely identifies a document?

12. MongoDB supports transactions?

13. Which operator matches values greater than?

14. Which operator pushes element to array?

15. Which language is MongoDB written in?

16. ObjectId contains?

17. Default storage engine?

18. Which tool validates schema?

19. Which stage limits results?

20. What type of database is MongoDB?

21. MongoDB document is similar to?

22. Replication provides?

23. MongoDB stores data in which format?

24. Best practice for schema?

25. Explain() shows?

26. Election occurs when?

27. TTL index works on?

28. Which operator checks equality?

29. MongoDB supports ACID?

30. MongoDB is?

31. MongoDB favors?

32. Text index is used for?

33. Sharding provides?

34. Which query is slow?

35. Which stage sorts documents?

36. CAP theorem stands for?

37. Which command shows all databases?

38. Which is valid MongoDB type?

39. Which command inserts a document?

40. Which operator matches less than?

41. GUI tool for MongoDB?

42. Which command deletes documents?

43. Document size limit?

44. Which command updates documents?

45. Oplog stores?

46. ACID stands for?

47. Which command finds documents?

48. Authorization controls?

49. Which operator calculates sum?

50. $facet is used for?

51. Shard key is?

52. Which operator matches array value?

53. $lookup works with?

54. Which role has full access?

55. Which command selects a database?

56. Oplog is?

57. Backup tool?

58. Default port of MongoDB?

59. Which operator sets a field value?

60. $elemMatch is used for?

61. deleteMany removes?

62. MongoDB schema is?

63. What is an index?

64. MongoDB collection is similar to?

65. Which operator increments value?

66. Poor shard key causes?

67. Restore tool?

68. Aggregation pipeline stage to filter?

69. Atlas provides?

70. Which improves performance?

71. $project is used for?

72. WiredTiger is?

73. Which node becomes primary?

74. Which command creates index?

75. $unwind does?

76. Which stage groups documents?

77. Compass is used for?