Eli5: Would Faraday Cages block Cell Signals well enough to utilize them in a classroom setting?

Question

I.e. ‘bricking the phone’ for the students benefit

In: Engineering

Answer 1

Put your phone inside the microwave

No don’t run the microwave, this isn’t one of those

With the microwave door closed try to call your phone

There’s your answer

btw if your phone can ring from inside a closed microwave it’s time for a new microwave