What color of light in the visible spectrum appears brightest? does this mean that it is the highest energy light?

The  answer is; yellow

This does  not mean that yellow light has the highest energy. Rather, blue color – that appears darkest, of the visible light colors, to the eye has the highest energy and the highest frequency. Red color (which comes after yellow in the electromagnetic spectrum) has the lowest energy and frequency.

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.

365.25 earth days are in the year of a light year