there are many 750s sold , by even NVidia and MSI and gigabyte
and more, and some are on long cards and others short.
what fits your unstated case can not be guessed.
then electrically the 750 comes in 2 power ratings.
one uses an AUX jack for a PSU v2.2 or higher and that connector. (do you have this connector? below)
one model 750 in fact only uses
is this s pre-buy question? or have the card now and forgot to tell full model numbers on the model sticker.?
The 750 is one of the best card that use low power, that is true.
so is the newer GTX1050 that I have, (buy this and be happy)
most the other video cards (faster for say gaming) all need more powerful PSU, that an aux power cable.
if you see this connector , here, you will need PSU that can
handle this cards power needs. ask.
there are many 750 made, some are faster and some are with
more memory and in some cases have this jack below AUX
the card will crash if you fail to connect this up, and if the PSU is
a gutless 200watt, that too will fail;
the 2 worst cards for power hogs is GTX690 and TITAN.
the full lists of cards and TDP (watts) is herehttps://en.wikipedia.org/wiki/List_of_Nvidia_graphics_processing_units