Do different universities offer different amounts of bridging courses? e.g. 3 or 7 weeks
Do you require a bridging course to enter into the course? Is it compulsory?
Different universities offer different programs, they run from anywhere from one day to thirteen weeks.
The better bridging programs will typically run for 5+ weeks at least.
The short programs can be slightly helpful if you're already moderately competent at the content, but to learn something you really need at least a few months in order for the content to sink in.
Most universities assume completion of cognate HSC studies as degree entry minimum, so tend not to require bridging courses (unless you are going into a degree not aligned with you HSC courses, in which case you may not be allowed to enroll unless you have done a bridging program or a special internal examination - This happen for example at my alma mater the university of Newcastle for engineering/math students who have not attained band 5 in advanced math, you either have to take a full extra course, take an invidulated bridging course, or pass a math placement exam, or you are not allowed to enroll in MATH1110 - Calculus 1).