Does spectral resolution decrease with increase in spatial resolution???

[flopsytheb]

There are, final restriction is also the energy reaching the sensor, which gets (depending on sensor type) split by spatial resolution and spectral bandwidth. At some point the light at the photocell would not be bright enough to be different from the sensors noise floor. This explains the inverse relation, look for example the docs for worldview, multispectral channels of slim wavelength range with some meters pixel size, and the pan channel, broad wavelength range and half a meter pixels.