Both Nikon D3200 and Canon T7 have APS-C sized 24.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the D3200 and T7 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D3200 and Canon T7 Cameras
Nikon D3200 and Canon T7 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
DxOMark Sensor Scores
Both Nikon D3200 and Canon T7 sensors have been tested by DxoMark. DxoMark scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Of the two cameras that we are comparing, D3200 has scored 81, 10 points higher than T7.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D3200
81
24.1 bits
13.2 Evs
1131 ISO
Canon T7
71
22.6 bits
11.9 Evs
1009 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Nikon D3200
or the
Canon T7 ,
including hyperfocal distance.
