If you use Google Forms to quiz users, you can grade multiple choice and checkbox questions automatically, to record a score for each person that submitted your form. Once a user fills in and submits your form, they will be able to review the questions and see which they answered correctly and incorrectly.
To turn on the quiz setting in a Google Form:
Click on the Settings cog near the top-right corner of the screen
Click on the Quizzes tab
Turn the Make this a Quiz setting to On
Choose how you would like users to see the quiz results, and what they can see after submitting their answers
Click on Save
To set the correct answer for a question:
Click on the question on the form
Click on the Answer Key link at the bottom of the answer list
Click on each correct answer for the question
Enter the number of Points awarded if the question is answered correctly
To provide feedback on correct and incorrect answers:
Click on Add answer feedback
Click on the Incorrect Answers tab and enter the feedback you wish to provide to the user if they answer incorrectly
To add a link to a website or video, click on the Link button, the enter the URL and text you wish to display, then click on Add
Click on the Correct Answers tab and enter any feedback and links to display when a user answers correctly
Click on Save when complete
If you set the quiz to show grades immediately after submission, the user will see a link to show their score after they have completed the form and clicked on the Submit button.
Each answer will show as correct or incorrect, with the relevant feedback displayed:
In your form, you can click on the Responses tab to view the score of each person that has submitted a form, and a summary of all responses.