What is the minimum energy required to ionize
a hydrogen atom in the n = 3 state?
(1) 0.00 ev (3) 1.51 ev
(2) 0.66 ev (4) 12.09 ev

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.