Hello tutors ! I need help with the following physics problem.

I need help with the following conceptual questions.

a) A source of electromagnetic waves radiates with powerPuniformly in all directions. At some distancedfrom the source, the magnetic field amplitude of the waves isB0. What will the amplitude of the magnetic field be a distanced/4 away from the source, in terms ofB0,P,d,₀,₀ , and/orc? Defend your answer.

b) You shine a flashlight due north and send it through a linear polarizer so that the light is vertically polarized. Along what direction does the magnetic field of that EM wave oscillate? (North-South, East-West, or Up- Down)? Defend your answer.