Is underexpose photo smaller in file size?

[sinori]

when compared to a good expose photo?:sweat:

 

[Michael]

when compared to a good expose photo?:sweat:

in a uncompressed RAW file exposure should have no effect on file size.
for compressed jpeg underexposure and the resulting large areas of black space may reduce file size... but this is not due to underexposure but due to more similar pixels in the pic... a correctly exposed photo of a monochrome surface should give just the same reduction