If your foot touches the line, you would be disqualified.
If your foot touches the line, you might be disqualified.
In the first sentence, there is absolutely no question, if you touch the line, you are automatically disqualified.
In the second sentence, there is doubt as to disqualification. If your foot touches the line, it MIGHT lead to you being disqualified, there is some amount of judgment that would be used.
So, "would be" is a certainty; "might be" is s possibility.