Electrostatics
What direction does the electric field point around a negative charge?
Toward the charge.
What physical property of materials determines the resistivity ρ at the microscopic level?
Electron scattering due to lattice vibrations and impurities.
What is the shape of the magnetic field around a long straight current-carrying wire?
Concentric Circles
What is required to induce a current in a loop of wire?
A changing magnetic flux
What two fields oscillate in an electromagnetic wave?
Electric and magnetic fields.
What happens to the electric potential when moving against the electric field?
It increases.
In a series circuit, is the voltage across each resistor the same or different?
Different
Describe the motion of a charged particle if its initial velocity has both parallel and perpendicular components relative to a uniform magnetic field.
Helical motion — constant-speed spiraling around the field direction.
What rule tells you the direction of the induced current
Lenz’s Law.
In what direction do the electric and magnetic fields oscillate relative to the direction of wave motion?
Perpendicular (transverse wave)
True or False: Conductors in electrostatic equilibrium have zero electric field inside them
True.
A capacitor stores energy in what form?
Electric Potential Energy
What happens to the direction of the magnetic force if the velocity of a charge is parallel to the magnetic field?
No force (force is zero).
If the magnetic flux through a coil increases, in what direction will the induced current flow?
To oppose the increase (producing its own opposing magnetic field).
What fundamental set of equations predicts electromagnetic waves?
Maxwell’s Equations.
A spherical shell has charge on its surface. What is the field just inside the shell? Why?
Zero — Gauss’s Law implies no enclosed charge inside the inner surface.
How does a dielectric inserted between capacitor plates affect the capacitance?
Increases it
True or False: Magnetic monopoles (isolated magnetic charges) have been found.
False
What happens to the induced current if the magnetic field is constant?
No induced current.
If the frequency of an electromagnetic wave increases, what happens to its wavelength?
It decreases.
Using Gauss’s Law, what is the field inside a uniformly charged solid conductor?
0 ( Zero )
In an AC circuit, what is the role of inductance at high frequencies?
It acts like a strong resistor
In a mass spectrometer, how does a magnetic field separate particles?
By causing curved paths depending on their mass-to-charge ratio.
A bar magnet is dropped through a copper loop. Describe the current as it falls and exits.
Current flows one way as it enters, reverses as it exits.
Light slows down in materials because of what physical effect?
Interaction with the material’s electric charges (causing delay in re-emission).