I have written and incorporated many socrative quizzes into my classroom teaching. Socrative is free web application (www.socrative.com) where you can set up a teacher account and can very rapidly write multiple choice and short answer tests.

After writing, you go to your virtual classroom and run the quiz, students then login to the room (with only their name), when you share the "room number" with them. They answer using their smartphones/tablets/laptops. Try enabling the randomize question option - which makes collaboration less likely ! Their responses and progress can be seen live on the "teacher dashboard"

I have found it particularly useful as a check on class progress. Its a very good opportunity to go and reteach only the theory that you can see they did poorly on. You can easily share the quiz with other teachers - here is one on that I wrote on the cardiovascular system to accompany the Eduqas specification SOC-20418911, if you go to the website and put in the number then you should be able to download and then use.

The students really enjoy the tests and the instant feedback, I recommend you give it a try.