My Lumia sounds an unknown ringtone when I place it near to my Delhi metro card, why is this?

[Windows Central Question]

my lumia sounds an unknown ringtone when i place it near to my delhi metro card

i randomly place my phone on my wallet, but i notice that my phone is ringing then i check my wallet, & then lastly it's the cause of my metro card. But i don't know why. Does it happen to anyone else??

 

[r2SN]

Re: my lumia sounds an unknown ringtone when i place it near to my delhi metro card

Well its surely due to the Delhi metro card. This is because the metro cards and the coins are embedded with "NFC" circuit. And your phone must definitely have NFC enabled,that's why when your card is near your phone it rings. I myself experimented with the cards and coins. Both the phone's NFC and the payment counter in metro stations work similarly and recognize the cards/coins using NFC and you get to pass.