Chapter 5 (Electricity, Magnetism, and Electromagnetism) Flashcards
What is the fundamental unit of electric charge?
Coulomb (C).
What does Ohm’s Law state?
V = IR (Voltage = Current × Resistance).
What is thermionic emission?
Electrons are boiled off from a heated filament.
What is a conductor?
A material that allows electrons to flow freely (e.g., copper).
What is an insulator?
A material that prevents electron flow (e.g., rubber).
What is a semiconductor?
A material that conducts electricity under certain conditions (e.g., silicon).
What type of current is used in x-ray tubes?
Direct Current (DC).
What is a step-up transformer used for?
Increases voltage for x-ray production.
What is a step-down transformer used for?
Reduces voltage to heat the filament.
What is the function of a rectifier?
Converts AC to DC.
What happens when resistance increases in a circuit?
Current decreases.
What are the units for power in an electrical circuit?
Watts (W).
What is magnetic induction?
The generation of an electric current by a moving magnetic field.
What is a superconductor?
A material with no electrical resistance at low temperatures.
What does an electromagnet consist of?
A coil of wire with current flowing through it.
What part of an MRI system uses electromagnetism?
The magnet and gradient coils.
What determines electrical resistance?
Material, length, and temperature.
What is a capacitor?
A device that stores electric charge.
What is the purpose of a circuit breaker?
Prevents excessive current flow.
What happens to electrons in a magnetic field?
They move in a circular or spiral path.
