Doesn't matter too much, but I'd go for the more generic Electric/Electronic over the computer one.
Yea, but I'm interested in how do circuits in computer hardware work e.g RAM, CPU, GPU and PCB. So I wanna know what would be the best for that, out of these two degrees ? Because I'm filling out my QTAC application for Queensland university's.
I think you are being too limited in your vision of your future.
You are trying to get an education that will enable you to have a good and interesting career for the next 40 years. In that time many
many things will change completely, and you will have to "adapt or die". A university course is the best way to get a solid theoretical understanding of the
basics of the things that you don't yet know you will need to know or want to know.
That can only happen if you have a relatively broad course.
One example of that (which you probably don't yet understand!) is that the only "digital" circuits involve photon counting and femtoamp circuits. All other circuits are really
analogue circuits where the transmitters have a limited range of output voltages/currents and the receivers
interpret their analogue inputs as being digital signals. And getting from the transmitter to the receiver is purely analogue - and RF with modern logic. The consequence is that to be able to design modern digital systems, you have to understand the analogue and RF operation. That will only get more extreme in the future.
Another point is that there are very few jobs in designing computers, and there will be fewer in the future. There are far more in using computers or designing interfaces or hardware/software systems. That requires understanding far more technical topics - and can be fascinating.
Finally, you can always learn about computer hardware work in your spare time. When your age I designed and built a computer (6800+128
bytes RAM). I made many mistakes, but got it working. That looked
very good on my CV when searching for my first job. (I made 12 applications, and had 19 job offers

)
Good luck and have fun.