Working in industry before pursuing a PhD in a different field I am an undergraduate student in mechanical engineering and would like to pursue my graduate studies in computational Physics in UK/US. The two subjects only align with respect to the 'computational' aspect, otherwise, they are pretty different. I have some relevant research in Physics.
But before applying for graduate schools, I'll have to work in the industry for a few years for financial reasons. My work in the industry will most likely be related to mechanical engineering,  such as structural analysis or aerospace engineering or with some luck, computational work.
How will working in the industry, say for 2-3 years in mechanical engineering, affect my graduate school application for Physics? Will it be a major disadvantage? If yes, is there anything I can do to counter that?
This answer may be valid only in the US.
The industry experience certainly won't be a plus, but as a minus it would probably be minimal. Can't predict precisely since every admissions committee is different and is composed of individuals.
But changing fields after a BS is pretty common here as is going back for a doctorate from the &quot;working world&quot;.
But, it will be essential, I think, that  you maintain contact with your current professors over that span so that they don't forget you and the (obviously) wonderful things you did as a student. You will still want good letters of recommendation from academics to pursue a doctorate. I think the supervisor of any physics research would be especially valuable to keep as a contact.
You could also, perhaps, take a graduate course or two as a &quot;non-matriculated&quot; student, which is permitted in some places. Or even some undergraduate physics courses that might be missing from your background.
But generally, look to what you will need to present in an application and work to assure that such things will still be available and valid.
And, the shorter the delay, the better.