Electric Fields 1. A wire has been given a net positive electric charge Q evenly distributed along its length. The wire has a length of L and is located on the x-axis with its left end at the origin as drawn. Set up the integral you need to do to find the electric field at a distance d to the left of the origin. Some steps you may wish to follow are: a. Figure out the direction the electric field will have at our location x = -d. This will be the same as f b. Write the differential charge dq in terms of the charge per length and a differential length. c. ris a function of x which means we have to integrate to find the electric field. Write down r. d. Put everything together (including the vector direction) into one integral that would allow you to find the E-field. Write this in the box below. e. You are not required to complete the integral and no credit is given for completing the integral.

1. An electron, a proton, an a particle (i.e. the He nucleus consisting of 2 protons and 2 neutrons), and a chlorine ion (CI) are shot into a uniform electric field, perpendicular to the field lines, all with the same speed. а. Sketch the trajectories of the three particles. Show clearly which curvature is the greatest, and which is the smallest. Label, which is which. b. Order the magnitudes of forces acting on the particles – the greatest to the smallest С. Order the accelerations of the particles – the greatest to the smallest E V particle

Q1

3. Assume a solid conductor is placed next to a negatively charged sphere. This causes the surface of the conductor near the sphere to become positively charged so that the net electric field inside the conductor is zero. Now we cut a hole so that it is entirely encased by the conductor. а. Does removing part of the inside of the conductor affect the electric field? cross-section of 3D conductor b. What the electric field inside the hole? c. Explain why sensitive equipment are often placed inside conductors. For example, circuit boards are typically shipped in foil-lined bags while cell phone signals are weaker inside warehouses with metal sides.