Question

The rod in Figure 15.49 carries a uniformly distributed positive charge. Which arrow (a–h) best represents the direction of the electric field at the observation location marked with a red X?

Short answer

Arrow hbest represents the direction of electric field at X.

Step-by-step solution

Given data

A rod with uniformly distributed positive charge.

Step 2:Electric field direction

Electric field from a positive charge distribution is directed away from the distribution.

Step 3:Determination ofthe direction of the field at the marked point

• The rod can be divided into several small sections. Fields from sections to the left of point X will have two components, one pointed up and one pointed right. Similarly, fields from sections to the right of point X will have two components, one pointed up and one pointed left.
• The net field will be the vector sum of all these fields. The upward components will all add up. The net horizontal component of the field can be obtained by subtracting the right components from the left.

• Since the X mark is a bit shifted towards the left from the center, the sum of left components will be larger. The net field at X will thus have an upward component and a left component. This can be best represented by arrow h.