Problem 13 Please Post A Complete Solution I Want To Be Able

Problem 13:

Please Post A Complete Solution I Want To Be Able Follow Your Work & Future Studnets With A Similar Problem Should Be Capable of Following Along. I Will Be Rating. Thank You.

Solution

Whenever you are given a closed surface,the magnetic flux through it will always be zero. This comes from fact that magnetic filed lines start and end at the same point. one couldalso aruge that since the magnetic field is unifrom, there is equal flux going into and coming out of the closed surface. Therefore net flux is zero