At a place a uniform electric field and a uniform magnetic field are in the upward direction. There an electron moves in the downward direction. Hence this electron .

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(3) will gain velocity. Given: ⃗E and ⃗B both point upward; an electron travels downward. Idea: use the Lorentz force ⃗F=q⃗E+q(⃗v×⃗B) with q=-e, and take the two parts separately. Magnetic part: ⃗v is antiparallel to ⃗B, so ⃗v×⃗B=0 — no magnetic force, and therefore no bending. Electric part: on a negative charge the force is opposite to ⃗E, so it points downward. That force lies along the electron's own motion, so it does positive work and the electron gains speed.

At a place a uniform electric field and a uniform magnetic field are in the upward direction. There an electron moves in the downward direction. Hence this electron ______.

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