Question 1
What is the primary purpose of Docker?
1
To manage physical servers
2
To compile code faster
3
To containerize applications for portability and efficiency
4
To create virtual machines
Question 2
Which command is used to list all running Docker containers?
1
docker list
2
docker ps
3
docker run
4
docker images
Question 3
What is the default network driver used by Docker containers?
1
Host
2
Overlay
3
Bridge
4
None
Question 4
Which file is used to define multi-container Docker applications?
1
Containerfile
2
docker-compose.yml
3
Dockerfile
4
Docker.yaml
Question 5
What is the primary purpose of a Dockerfile?
1
To run database services
2
To define system dependencies
3
To store container logs
4
To create and build Docker images
Question 6
Which command is used to remove a stopped container?
1
docker rm <container_id>
2
docker rmi <container_id>
3
docker stop <container_id>
4
docker remove <container_id>
Question 7
How do you start an interactive shell inside a running container?
1
docker exec -it <container_id> /bin/bash
2
docker shell <container_id>
3
docker run -it <container_id>
4
docker attach <container_id>
Question 8
What is the difference between docker stop and docker kill?
1
They are identical commands
2
docker stop sends a graceful termination signal, while docker kill forcefully stops the container
3
docker kill can only be used on stopped containers
4
docker stop immediately kills the container, while docker kill sends a termination signal
Question 9
What is a Docker volume used for?
1
Managing container logs
2
Automating deployments
3
Running multiple containers
4
Storing persistent data outside of containers
Question 10
How do you remove an unused Docker image?
1
docker rmi <image_id>
2
docker delete <image_id>
3
docker image prune
4
docker remove image <image_id>
Question 11
What is a Docker image?
1
A running instance of a container
2
A backup file for Docker
3
A template used to create Docker containers
4
A virtual machine
Question 12
Which Dockerfile instruction sets the base image?
1
CMD
2
BASE
3
FROM
4
RUN
Question 13
What does the docker build command do?
1
Downloads an image
2
Starts a new container
3
Creates a container image from a Dockerfile
4
Pushes an image to Docker Hub
Question 14
What is Docker Hub?
1
A local storage for containers
2
A dashboard tool
3
A cloud-based repository for Docker images
4
An IDE for Docker
Question 15
What is the purpose of the EXPOSE instruction in a Dockerfile?
1
Maps container ports to the host
2
Documents the port the container listens on
3
Runs a command on a specific port
4
Opens a port in the Docker host firewall
Question 16
Which command is used to push a Docker image to Docker Hub?
1
docker export
2
docker upload
3
docker push
4
docker save
Question 17
What is the function of CMD in a Dockerfile?
1
Builds the image
2
Installs system packages
3
Specifies the command to run when a container starts
4
Declares environment variables
Question 18
What does docker logs <container> do?
1
Shows real-time logs from the container’s stdout and stderr
2
Deletes all logs
3
Lists running containers
4
Opens a shell inside the container
Question 19
Which of the following is true about Docker containers?
1
Containers cannot run on Windows
2
Containers are slower than virtual machines
3
Containers share the host OS kernel
4
Each container includes a full operating system
Question 20
What does docker-compose up do?
1
Builds and starts all services defined in docker-compose.yml
2
Installs Docker
3
Pulls images from Docker Hub without starting them
4
Removes all containers
Question 21
What happens if you run a container with a volume and the target folder inside the container already has data?
1
The container's data is preserved
2
Docker throws an error
3
The host directory overwrites the container directory
4
Data is merged
Question 22
Which networking mode allows Docker containers to share the host’s network stack?
1
macvlan
2
overlay
3
bridge
4
host
Question 23
What is the difference between COPY and ADD in a Dockerfile?
1
ADD is faster than COPY
2
No difference
3
COPY is older than ADD
4
ADD can fetch remote URLs and unpack archives
Question 24
Which of the following best describes a multi-stage Docker build?
1
Using multiple containers in parallel
2
Using one Dockerfile with multiple FROM instructions
3
Combining multiple base images in one build
4
Running multiple build commands at once
Question 25
You want to ensure a container restarts if it crashes. Which restart policy should you use?
1
always
2
unless-stopped
3
no
4
on-failure
Question 26
What’s the purpose of .dockerignore file?
1
It prevents files from being copied to the host
2
It hides logs
3
It excludes files from image build context
4
It disables Dockerfile execution
Question 27
What does the ENTRYPOINT instruction do differently from CMD?
1
It is overridden by Docker run arguments
2
It cannot be changed
3
It runs only once
4
It sets the main command that cannot be replaced by arguments
Question 28
How do you run a container in detached mode with an environment variable?
1
docker run --detach --env ENV=production image
2
docker run -d ENV=production image
3
docker start -e ENV=production image
4
docker run -e -d ENV=production image
Question 29
Which component is used for orchestrating multi-host Docker deployments?
1
Docker Network
2
Docker Swarm
3
Docker Compose
4
Docker Machine
Question 30
What does the --mount flag provide that -v (volume) does not?
1
Read-only support
2
Container restart on change
3
Named volumes
4
Clear syntax and extra options like consistency and caching