Suppose I have a standard credit card with a magnetic stripe, lying
- right on top of a cellphone, or
- in a regular leather wallet that's lying right on top of a cellphone.
The cellphone is on (but not in a call), uses a 3G network, and is in a good reception area.
Will the credit card be demagnetized (to the point where it can't be read) in the above 2 scenarios? If so, how long will it typically take? An answer that shows all assumptions and calculations used would be especially useful!