2 Minute Countdown to answer questions

Would adding a countdown timer for 2 minutes to answer a small number of questions (let's say 5 to 10 questions) add too much stress to the user?

I'm thinking about users that aren't the best at taking exams or worried about the timer running out so they rush through the questions and make possible mistakes?

Our scenario is:

We give the user a warning 2 minutes before they start the questionnaire.

Once they hit next, the questionnaire starts (5 questions to make sure it's the person they say they are).

Our older system had a countdown timer that counted down and flashed. I was under the impression that this is a negative user experience and caused the user to rush and fail more often.

I'd like to implement an easier/less stressful timer/countdown for the user.