A 180 v battery is connected across two parallel metal plates of area 28.5 cm2cm2 and separation 7.20mm. A beam of alpha particles (charge +2e+2e, mass 6.64x10-27kg6.64×10-27kg) is accelerated from rest through a potential difference of 1.50 kV and enters the region between the plates perpendicular to the electric field, What magnitude of magnetic field is needed so that the alpha particles emerge undeflected from between the plates? Express your answer with the appropriate units. What is the direction of this magnetic field? 田 The magnetic field is directed out of the page. The magnetic field is directed upward. OThe magnetic field is directed into the page. C The magnetic field is directed downward.

A 180 v battery is connected across two parallel metal plates of area 28.5 cm2cm2 and separation 7.20mm. A beam of alpha particles (charge +2e+2e, mass 6.64x10-27kg6.64×10-27kg) is accelerated from rest through a potential difference of 1.50 kV and enters the region between the plates perpendicular to the electric field, What magnitude of magnetic field is needed so that the alpha particles emerge undeflected from between the plates? Express your answer with the appropriate units. What is the direction of this magnetic field? 田 The magnetic field is directed out of the page. The magnetic field is directed upward. OThe magnetic field is directed into the page. C The magnetic field is directed downward.