Calculate the three lowest energy levels, together with their degeneracies, for the following systems (assume equal-mass distinguishable particles). (a) Three non interacting spin 12 particles in a box of length L.
(b) Four noninteracting spin 12 particles in a box of length L.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

i believe the answer would be:

d. violin, clarinet, french horn, and tuba