ATAR Notes: Forum

HSC Stuff => HSC Science Stuff => HSC Subjects + Help => HSC Physics => Topic started by: BlackFrost on February 24, 2021, 12:31:22 pm

Title: Magnetic flux and EMF question
Post by: BlackFrost on February 24, 2021, 12:31:22 pm

Hi, could someone please explain how to do this question - I am really confused about why the EMF changes value (increase, decrease), why it becomes 0, and changes directions in terms of the magnetic flux formula. Thank you !!!

Title: Re: Magnetic flux and EMF question
Post by: fun_jirachi on February 25, 2021, 05:32:50 pm

The emf changes based on the change in flux over time. Usually, the emf will fluctuate when the field changes in strength, it moves from one field to another (both differing in strength), if it speeds up or slows down in a magnetic field, rotates, etc. At Q and S, no such change occurs, and hence the emf is 0. Considering the formula as well, an increase in field strength would alter the emf in the opposite direction compared to a corresponding decrease in field strength. Think about what actually happens at P and R that could change the emf (especially with respect to Faraday's Law, this will make it easier to understand).

Hope this helps :)