1. A charged particle, passing through a certain region of space, has a velocity whose magnitude and direction remain constant. (a) If it is known that the external magnetic field is zero everywhere in the region, can you conclude that the external electric field is also zero? Explain. (b) If it is known that the external electric field is zero everywhere in the region, can you conclude that the external magnetic field is also zero? Explain. 2. Determine the magnetic field direction that causes the charged particle shown below to experience the indicated magnetic force. (a) (b) V V + F Into the page