1. Which of the following is true about MongoDB?
a) MongoDB is a relational database
b) MongoDB is a NoSQL database
c) MongoDB is an object-oriented database
d) MongoDB is a graph database
View Answer
Answer: b) MongoDB is a NoSQL database
Answer Explanation: MongoDB is a NoSQL database, which means it does not use the traditional SQL-based relational model for storing data.
2. Which of the following is NOT a characteristic of MongoDB?
a) High scalability
b) Flexible data model
c) Consistency in data replication
d) High availability
View Answer
Answer: c) Consistency in data replication
Answer Explanation: MongoDB provides eventual consistency, which means that updates to the database may take some time to propagate to all nodes in a distributed cluster.
3. Which data format is used by MongoDB?
a) XML
b) JSON
c) YAML
d) CSV
View Answer
Answer: b) JSON
Answer Explanation: MongoDB uses JSON (JavaScript Object Notation) as its primary data format.
4. Which of the following is NOT a benefit of using MongoDB?
a) High performance
b) Schemaless data model
c) Flexible queries
d) Data integrity and constraints
View Answer
Answer: d) Data integrity and constraints
Answer Explanation: MongoDB does not provide built-in data integrity and constraints, as it is designed for flexible and schemaless data storage.
5. What is a “document” in MongoDB?
a) A table in a relational database
b) A collection of related fields
c) A unit of data in a NoSQL database
d) A query language used to retrieve data
View Answer
Answer: c) A unit of data in a NoSQL database
Answer Explanation: In MongoDB, a document is a unit of data storage, similar to a row in a relational database.
6. Which of the following is a valid data type in MongoDB?
a) Boolean
b) Double
c) String
d) All of the above
View Answer
Answer: d) All of the above
Answer Explanation: MongoDB supports a variety of data types, including Boolean, Double, and String.
7. What is the role of a “collection” in MongoDB?
a) It defines the structure of a document
b) It is a group of related documents
c) It provides a schema for the database
d) It is a type of index used for querying data
View Answer
Answer: b) It is a group of related documents
Answer Explanation: In MongoDB, a collection is a group of related documents that are stored together. Collections are analogous to tables in a relational database.
8. Which of the following is NOT a type of index supported by MongoDB?
a) Single-field index
b) Compound index
c) Multikey index
d) Hierarchical index
View Answer
Answer: d) Hierarchical index
Answer Explanation: While MongoDB supports single-field, compound, and multikey indexes, it does not support hierarchical indexes.
9. What is a “shard” in MongoDB?
a) A type of data model used for hierarchical data
b) A subset of a MongoDB database
c) A distributed cluster of MongoDB nodes
d) A type of query used for joining data
View Answer
Answer: c) A distributed cluster of MongoDB nodes
Answer Explanation: A shard in MongoDB is a distributed cluster of nodes that collectively store a subset of the data in a database. Sharding is used for horizontal scaling of data storage and processing.
10. What is the default write concern in MongoDB?
a) 1
b) 0
c) majority
d) all
View Answer
Answer: a) 1
Answer Explanation: The default write concern in MongoDB is “1”, which means that the write operation must be acknowledged by at least one node before it is considered successful.