This is a simple (and well-known) game you can do in groups of 3-10 people.
If you have a big class, and you know your students can work for a good amount without supervision, you can divide them class off into groups without you playing with them.
OBJECTIVE: Students must guess what card they are holding by asking only yes or no questions.
Preparation and Materials:
1) Cards with nouns
Avoid using famous people if you are not sure if the students know them. You can adjust the game's difficulty by choosing easier or harder words.
2) Sample questions to ask
For low level students, just like the picture above, you may want to provide your students a cheat sheet of questions they can ask their group members.
If you do not have time, you can easily just google some easy nouns that your students will know, print them out and cut it into individual pieces of paper. Prepare some tape and have the students themselves tape the paper on their group member's backs.
Remind your students that they can only ask yes or no questions.
A bunch of my students forget and always end up asking stuff like "what colour am I" or something like that. Demonstrate what's a OK question to ask, and what's an NG question to ask.
This website has a good PDF file you can edit to make your own cards.
It also has variations of the game you can use to change up your activity for several classes if you need to, so your students don't get bored and you can reuse your materials multiple times.