DX lens effective focal length?

After understanding the difference between FX and DX and their pro's and con's now there's a new growing perplexity. What would be the focal length if a Nikon DX format 35mm prime is used with Nikon d7100. Will the focal length be the same 35mm or the added crop factor of 1.5x would covert it to a 52.5mm. Does crop factor apply to all Nikon DX format lenses?

If the camera is a DX format sensor you should have little to no cropping in the image if it has an FX sensor you will suffer from cropping, making the final image a small mm than the lens' listed mm.

Nikon uses "DX" to designate their cropped sensor cameras and the lenses designed for them. A Nikon "DX" format DSLR has a crop factor of 1.5x. This was originally used to allow a photographer switching from 35mm film (known today as full-frame or "DX" format) to determine the coverage their lenses from their 35mm film camera would have on a "DX" format DSLR.

So a photographer using a 24mm lens multiplied by 1.5 and knew his coverage would be equivalent to a 36mm lens. So to achieve the same amount of coverage he either backed up or switched to a 16mm lens. (16 x 1.5 = 24mm)

Note that the actual focal length of the lens is always the same. What changes is the equivalent angle of view.

One MAJOR advantage Nikon has over Canon is that a "DX" lens CAN be used on an "FX" body - the full-frame body simply crops the sensor the the "DX" size. Yes, some of the resolution of the "FX" sensor is lost but at least the "DX" lens is still usable.

A Canon EF-S lens is totally unusable on a Canon full-frame DSLR. Someone who buys a Canon cropped sensor DSLR and a couple of EF-S lenses has to replace those EF-S lenses should they upgrade to a Canon full-frame body.