Q: Can I able to read cameras and USB in my I-pad4?

Kinda.

You cannot use it to read or transfer data files or music. Properly formatted and using the right naming convention you can use USB to transfer photos and videos to your iPad. But not off. there is zero support to transfer anything off the iPad via the USB.

the catches are:

Only some USB's work. I've experienced a 50/50 success rate using a variety of brand name and no name drives.

The iPad will only see video or photo files on the drive that mimic how a camera names them. So there must be a folder named DCIM and everything in it must be in a format the iPad will read and have eight character names, for example DSC_3849.jpg.

You can only preview thumb nails off the drive, to see the photo full size you must import it into your ipad.

You can use a USB flash drive & the camera connection kit.

Plug the USB flash drive (works the same with an SD card) into your computer & create a new folder titled DCIM. Then put your movie/photo files into the folder. The files must have a filename with exactly 8 characters long (no spaces) plus the file extension (i.e., my-movie.mov; DSCN0164.jpg).

Now plug the flash drive into the iPad using the camera connection kit. Open the Photos app, the movie/photo files should appear & you can import. (You can not export using the camera connection kit.)

Using The iPad Camera Connection Kit

http://support.apple.com/kb/HT4101

Secrets of the iPad Camera Connection Kit

http://howto.cnet.com/8301-11310_39-57401068-285/secrets-of-the-ipad-camera-conn ection-kit/

 Cheers, Tom