I have a dell Inspiron 3470 desktop with a 200 watt power supply what graphics card can i put in it?

A GT 1030 should be fine. The card draw is low and the graphics will be much better than the Integrated CPU graphics. At Techpowerup here, they recommend a 200W PSU. Also make sure to purchase the 1030 with GDDR5 memory and NOT GDDR 4. Also make sure you get a 1030 with the low profile bracket.

Make sure whatever you get is LP (low-profile) version with short bracket.

Quadro's P400, 600, & 1000

Edited from PC Parts Bin:

Direct X 12 GPU's for modern rendering:

GT 1030 GDDR5  (As mention by JOcean.)

RX 550

RX 6400

Direct X GPU's for previous decade rendering:

AMD R7 200 series (previous and branded from the ATI HD series graphics cards)  Important - Check wattages.

GT 710, 720, & 730

GTX 750