I am trying to install Noobs on on a SD card. I don't have access to a SD card reader so I have inserted my SD card into my mobile and plugged it into the laptop. Now Disk Imager does not recognize the sd card since it is located inside the phone. How do I install Noobs?
You don't need to use disk imager. You should be able to install NOOBS by downloading the zip file from here and extracting the files onto the SD card, assuming the file explorer on your computer can read the card.