---
title: Motion of Charges in Fields 3
topic: Magnetism
author: John Hopkinson
source: PHYS122 2018W2 Q9
template_version: 1.4
attribution: standard
partialCredit: true
singleVariant: true
outcomes:
- 19.3.2.0
difficulty:
- undefined
randomization:
- undefined
taxonomy:
- undefined
span:
- undefined
length:
- short
tags:
- JR
assets:
- MotionOfCharge3.png
part1:
  type: multiple-choice
  pl-customizations:
    fixed-order: true
    weight: 1
myst:
  substitutions:
    params:
      vars:
        title: Motion of Charges in Fields 3
      part1:
        ans1:
          feedback: ''
        ans2:
          feedback: ''
        ans3:
          feedback: Yes, the right hand rule tells us that the magnetic field acting
            on a positively charged particle creates a force acting on a particle
            initially moving out of the page. This creates a spiral motion as the
            parallel component of the velocity vector to the magnetic field is not
            changed.
        ans4:
          feedback: ''
        ans5:
          feedback: ''
---
# {{ params.vars.title }}
Consider the charge $q>0$ moving in a constant magnetic field $\vec{B}$ as shown below.

<img src="MotionOfCharge3.png" width=400 alt="On the left is a diagram of a positive charge moving up and to the right in a magnetic field that points up the page. On the right are arrows representative of the charge's possible trajectories. The arrow for option a starts pointing up and to the right and bends parabolically upward. The arrow for option b shows a spiral trajectory. The charge moves up the page and rotates counterclockwise as seen by an observer looking down the page. The arrow for option c shows a spiral trajectory. The charge moves up the page and rotates clockwise as seen by an observer looking down the page. The arrow for option d shows a circular trajectory. The charge rotates counterclockwise as seen by an observer looking down the page. The arrow for option e starts pointing up and to the right and bends parabolically downward.">

## Part 1

Choose the correct path that the particle follows.

### Answer Section

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- {{ params.part1.ans2.value }}
- {{ params.part1.ans3.value }}
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## Attribution

Problem is licensed under the [CC-BY-NC-SA 4.0 license](https://creativecommons.org/licenses/by-nc-sa/4.0/).<br> ![The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.](https://raw.githubusercontent.com/firasm/bits/master/by-nc-sa.png)