Docker MCQs with answers Page - 34

Dear candidates you will find MCQ questions of Docker here. Learn these questions and prepare yourself for coming examinations and interviews. You can check the right answer of any question by clicking on any option or by clicking view answer button.
Share your questions by clicking Add Question

Q. What is the purpose of the `FROM` instruction in a Dockerfile?

  • (A) To define environment variables
  • (B) To specify the base image
  • (C) To expose ports
  • (D) To start a container
💬 Discuss
✅ Correct Answer: (B) To specify the base image
Explanation: `FROM` sets the base image for the Docker image being built.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. Which Dockerfile instruction copies files from the host system to the container?

  • (A) MOVE
  • (B) GET
  • (C) COPY
  • (D) PASTE
💬 Discuss
✅ Correct Answer: (C) COPY
Explanation: `COPY` copies files and directories from the host machine to the image.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. What is the function of the `CMD` instruction?

  • (A) Defines the image entry point
  • (B) Runs during the build process
  • (C) Provides default arguments for the container
  • (D) Builds the image
💬 Discuss
✅ Correct Answer: (C) Provides default arguments for the container
Explanation: `CMD` provides defaults for executing the container.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. Which instruction sets the working directory inside a Docker container?

  • (A) WORKINGDIR
  • (B) DIR
  • (C) WORKDIR
  • (D) SETDIR
💬 Discuss
✅ Correct Answer: (C) WORKDIR
Explanation: `WORKDIR` sets the working directory for instructions like `RUN`, `CMD`, etc.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. What does the `EXPOSE` instruction do in a Dockerfile?

  • (A) Opens a file
  • (B) Publishes a container to a repository
  • (C) Informs Docker that the container listens on a port
  • (D) Starts a process
💬 Discuss
✅ Correct Answer: (C) Informs Docker that the container listens on a port
Explanation: `EXPOSE` documents which ports are intended to be published.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. How can you specify environment variables in a Dockerfile?

  • (A) SETENV
  • (B) ENV
  • (C) VARIABLE
  • (D) DEFINE
💬 Discuss
✅ Correct Answer: (B) ENV
Explanation: The `ENV` instruction sets environment variables.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. Which Dockerfile instruction is used to add metadata to an image?

  • (A) LABEL
  • (B) ENV
  • (C) META
  • (D) INFO
💬 Discuss
✅ Correct Answer: (A) LABEL
Explanation: `LABEL` provides metadata as key-value pairs.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. Which instruction is used to run scripts after a container starts?

  • (A) RUN
  • (B) CMD
  • (C) SCRIPT
  • (D) AFTER
💬 Discuss
✅ Correct Answer: (B) CMD
Explanation: `CMD` is used to provide the default command for a container when it starts.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. How can you copy files with permissions preserved?

  • (A) COPY --chmod
  • (B) ADD
  • (C) RUN copy
  • (D) EXPORT
💬 Discuss
✅ Correct Answer: (A) COPY --chmod
Explanation: `COPY` supports the `--chmod` flag to set file permissions.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Q. Which instruction allows downloading and extracting tar files automatically?

  • (A) COPY
  • (B) GET
  • (C) ADD
  • (D) RUN
💬 Discuss
✅ Correct Answer: (C) ADD
Explanation: `ADD` can download and extract compressed tar files.

Published by Mr. Dubey ⭐ 111.54K Points at 24-Jul-2025 07:07 am in Docker

Programming Categories

📱 Download Our App

Learn MCQs on the go with our easy-to-use Android app

Get it on Google Play