Download Objectives for Material to be Learned from Unit 1

Physics 212
Classical and Modern Physics
Spring 2017
Objectives for Material to be Learned from Unit 1
By the end of this unit, students should be able to do the following:
1.1 (Continuing objective) Describe applications of the concepts of electricity and magnetism to
everyday “real-life” situations.
1.2 Use Coulomb’s Law to calculate electric forces. Specifically, for a given configuration of a
small number of point charges, calculate the total electric force (magnitude and direction)
acting on any chosen charge, due to all the others.
1.3 For a point charge or a configuration of several point charges, calculate the electric field
(magnitude and direction) at any given location.
1.4 Relate the electric force on a charge to the electric field at the location of the charge.
1.5 Describe the physical difference between conductors and insulators.
1.6 Show (using sketches) how the proximity of a charged object causes redistribution of charge
in a nearby object. Explain how this can result in attractive forces.
1.7 From a physical sketch or verbal description of a continuous line or line segment of charge,
perform the following steps in setting up the calculation of the electric field at a given point
P . (a) Make a sketch, and choose a coordinate system and an integration variable. (b) On
the sketch, mark a “non-special” piece of charge dq, and label its size using dx or dy or Rdθ
as appropriate. (c) Generate correct expressions for r and dq, in terms of the integration
variable. Substitute these expressions into dE = kdq/r2 to determine dE from the marked
piece of charge. (d) Determine the correct limits of integration. (e) Determine the geometric
factors by which dE should be multiplied to get the components (dE)x and (dE)y . (f)
Integrate (dE)x and (dE)y to find the components of the total electric field.
1.8 Represent and interpret electric fields using both field line and vector field diagrams.
1.9 Use Gauss’s Law to relate electric flux through a closed surface to the net enclosed charge.
1.10 Use Gauss’s Law to calculate the electric fields due to symmetric charge distributions.
~ to the potential difference between two points in the
1.11 For a uniform electric field, relate E
field.
1.12 Calculate the electric potential for a system of point charges, using superposition.
1.13 For a given physical arrangement of charges and fields, relate electric potential difference,
potential energy change, work, and kinetic energy change.
1.14 Use the definition of current and Ohm’s Law to relate current, charge, potential difference,
and resistance.
1.15 Calculate the power produced or required by an electric system, given an appropriate combination of voltage, current, and resistance.
1.16 Correctly sketch the direction of the magnetic field in the vicinity of variously shaped magnets,
especially near the North or South poles.
1.17 Calculate the cross product of two vectors, determining both its magnitude and direction.
1.18 Calculate the force (magnitude and direction) acting on moving charges and current-carrying
conductors in a magnetic field.
1.19 Starting from Newton’s 2nd law, relate the velocity, magnetic field strength, and radius of
curvature for a particle moving in a uniform magnetic field.
1.20 For a current loop or coil in a uniform magnetic field, calculate the magnetic moment, the
torque on the coil, and the magnetic energy.
1.21 Use the Biot-Savart law and the right-hand rule to determine the magnitude and direction of
a magnetic field due to a short current segment.
1.22 Distinguish and correctly use the expressions for the magnetic field for each of these special
situations: (a) at the center of a circular loop or finite arcs of a circular loop; (b) inside and
just outside the central region of a very long solenoid, (c) outside a wire segment or long
straight wire. Use these and superposition to find the total B-field due to a combination of
sources.
~ (circulation) to the net encircled current.
1.23 Use Ampere’s Law to relate the loop integral of B
1.24 Use Ampere’s Law to calculate the magnetic fields due to symmetric steady currents.
Lab Objectives for the first unit (Labs 13-15)
• Lab 13: DC Circuits
– Know the meaning of the terms current, voltage, and potential difference as well as the
proper placement and purpose of a voltmeter or an ammeter in a DC circuit.
– Be able to read and draw circuit diagrams.
– Know how to apply Kirchhoff’s Rules for circuits.
– Be able to apply Ohm’s Law to calculate resistance, voltage, or current in a simple
circuit.
• Lab 14: Charged Particles in Fields
– Be able to predict qualitatively the behavior of a charged particle beam in a magnetic
field using the magnetic force law and the right hand rule.
– Describe the forces acting on a charged particle in a uniform magnetic field, and be able
to use these forces along with Newton’s second law to analyze the motion of the charged
particles.
– Be able to identify the components of the “e/m” apparatus, such as the accelerating
voltage and Helmholtz coils.
– Know how the radius of the circular path of a charged particle beam in a magnetic field
depends on the experimentally adjustable quantities of the “e/m” apparatus.
– Know the orientation of the magnetic field in the vicinity of a bar magnet.
• Lab 15: Motors and Generators
– Describe how simple DC electric motors and electric generators work.
– Use the right hand rule to determine which way a current-carrying conductor will move
in a magnetic field.
– Be able to describe the results of each of the small experiments/tests that you did in the
Motors and Generators lab.
– For all of the experiments with forces on wires and motors, be able to explain the
behavior using forces on currents and torques on dipoles in magnetic fields, and be able
to use the right hand rule to determine directions.
– For the experiments that generated currents, be able to explain what the experiment
implies about inducing electrical currents.