PHYS 251: RC Circuits and Magnetic Fields

These flashcards cover key concepts related to RC circuits and magnetic fields discussed in the lecture.

Capacitance

The ability of a system to store charge per voltage, calculated as C = Q/ΔV.

Time Constant (τ)

A measure of the time it takes for the charge or voltage across a capacitor to either charge or discharge, expressed as τ = RC.

Discharging

The process by which a charged capacitor releases its stored charge through a resistor.

Charging

The process by which a capacitor collects charge from a battery until it reaches the battery voltage.

Voltage (ΔV)

The electric potential difference that drives the current and charge in circuits.

Current (i)

The flow of electric charge, often measured in amperes (A).

Electric Dipole

A pair of equal and opposite charges separated by a distance.

Magnetic Field (B)

A vector field surrounding magnetic materials and electric currents, influencing the behavior of charged particles.

Right-Hand Rule (RHR)

A method to determine the direction of the magnetic field surrounding a current-carrying conductor.

Saturation Decay

The slow decrease in current or charge that occurs over time as a capacitor discharges.

Charge (Q)

The electrical property of matter that causes it to experience a force when placed in an electromagnetic field.

Resistor (R)

A component that opposes the flow of electrical current, dissipating energy as heat.

Battery (Vo)

A device that provides electric energy in the form of voltage.

Electric Field (E)

A field surrounding an electric charge that exerts a force on other charges within the field.

Gaussian Unit (Gauss)

A unit of measurement for magnetic field strength; 1 Tesla equals 10,000 Gauss.

Right Hand Rule Example

The Right Hand Rule (RHR) is used to determine the direction of the magnetic field surrounding a current-carrying conductor. Here are some examples of how to use the Right Hand Rule:

1. Straight Conductor:

   • Point your thumb in the direction of the current (I).

   • Your fingers will curl around the conductor in the direction of the magnetic field (B).

2. Loop or Coil:

   • Curl your fingers in the direction of the current flowing through the loop.

   • Your thumb will then point in the direction of the magnetic field at the center of the loop.

3. Force on a Current-Carrying Wire in a Magnetic Field:

   • Use your thumb to point in the direction of the current (I), your index finger in the direction of the magnetic field (B), and your middle finger will point in the direction of the force (F) acting on the