All of the tablet students who were allowed to take the test said they were preparing to incorporate PDF into a document. In the tablet's OpenBook exam, the important position in the tag document does not seem to be as important as in the wifi jammer test. The search function in PDF makes it easier to find a specific location. However, some teachers see the problem: "students search faster and need to know less about documents."

https://www.jammer-buy.com/cell-phone-jammer/c-24.html

I think it's been almost two years since I first heard of "EMP signal jammer", and I've seen all kinds of video on Youtube to make one. Over the last two weeks, I've spent some time trying to build an electromagnetic pulse generator (EMP) from video and images on the Internet.

Using Emp Jam Jam, strictly speaking, there is no Emp generator at all, but only one "emitter" generates a few MHZ emission frequencies. This interferes with electronic circuits such as calculators and alarm clocks. In addition, you can do cool things with them using fluorescent lights or energy saving lights, instead of connecting them to energy.

https://www.jammer-buy.com/wifi-jammer/c-29.html