A student used a PhET simulation to investigate factors that affect the strength of electromagnets. Which of the following is the best explanation of the position of the of the compass needle in the investigation? a. The needle is aligned with the coil.
b. The needle is aligned with the electrical field from the battery.
c. The needle is aligned with the magnetic field from the coil.
d. None of the above

Efficiency is an action of doing something. for example when you take a test. good efficiency means you did well but bad effeciency or no effiency means you did bad.

Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.