Electromagnetism Flashcards
What is the basic principle behind electromagnetism?
Electromagnetism is the interaction between electric charges and magnetic fields.
True or False: Electric fields can exist independently of magnetic fields.
True
What is the unit of electric charge?
Coulomb (C)
Fill in the blank: The force between two charged objects is described by __________ Law.
Coulomb’s
What is the formula for calculating the electric force between two charges?
F = k * (|q1 * q2| / r^2)
What does the variable ‘k’ represent in Coulomb’s Law?
Coulomb’s constant
Define electric field.
An electric field is a region around a charged particle where a force would be exerted on other charges.
What is the unit of electric field strength?
Volts per meter (V/m)
True or False: Magnetic fields are produced by moving electric charges.
True
What is the unit of magnetic field strength?
Tesla (T)
What is the right-hand rule used for in electromagnetism?
To determine the direction of the magnetic field around a current-carrying conductor.
Fill in the blank: A __________ is a material that can be magnetized.
magnet
What does Ohm’s Law state?
V = I * R, where V is voltage, I is current, and R is resistance.
True or False: Resistance is directly proportional to the length of a conductor.
True
What is a capacitor used for?
To store electrical energy in an electric field.
What is the unit of capacitance?
Farad (F)
Define inductance.
Inductance is the property of a conductor that opposes a change in current.
What is the unit of inductance?
Henry (H)
What is Faraday’s Law of Electromagnetic Induction?
The induced electromotive force in a circuit is proportional to the rate of change of magnetic flux through the circuit.
What is Lenz’s Law?
Lenz’s Law states that the direction of induced current is such that it opposes the change in magnetic flux.
Fill in the blank: The magnetic field lines around a magnet always form __________ loops.
closed
What is the difference between AC and DC current?
AC (Alternating Current) changes direction periodically, while DC (Direct Current) flows in one direction.
What is the formula for calculating power in an electrical circuit?
P = V * I
True or False: Superconductors have zero electrical resistance.
True
What is an electromagnet?
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
What happens to the magnetic field of an electromagnet when the current is turned off?
The magnetic field disappears.
Fill in the blank: The __________ effect describes the production of voltage across a conductor when it is exposed to a changing magnetic field.
induction
What is the role of a transformer in an electrical circuit?
To increase or decrease voltage levels in AC circuits.
What is the principle of operation of a transformer?
Electromagnetic induction.
Define magnetic flux.
Magnetic flux is the measure of the quantity of magnetism, taking into account the strength and the extent of a magnetic field.
What is the unit of magnetic flux?
Weber (Wb)
What is the relationship between current, voltage, and resistance in a circuit?
Ohm’s Law: V = I * R.
True or False: Electromagnetic waves require a medium to travel through.
False
What is the speed of light in a vacuum?
Approximately 3 x 10^8 meters per second.
What is the electromagnetic spectrum?
The range of all types of electromagnetic radiation, from radio waves to gamma rays.
Fill in the blank: The __________ is the region of space around a charged particle where it exerts a force on other charged particles.
electric field
What is the term for the opposition that a circuit offers to the flow of electric current?
Resistance
What device is used to measure electric current?
Ammeter
What is a magnetic pole?
Either of two regions at opposite ends of a magnet where the magnetic force is strongest.
True or False: Like poles of magnets repel each other.
True
Fill in the blank: The __________ is a material that allows electric current to flow easily.
conductor
What is the principle behind electric generators?
Converting mechanical energy into electrical energy through electromagnetic induction.
What is the role of a fuse in an electrical circuit?
To protect the circuit by breaking the connection when the current exceeds a certain level.
What type of wave are electromagnetic waves?
Transverse waves
Fill in the blank: The frequency of a wave is the number of __________ that pass a point in one second.
cycles
What does the term ‘ground’ refer to in electrical circuits?
A common return path for electric current.
What is the purpose of shielding in electrical systems?
To protect sensitive components from electromagnetic interference.
True or False: Electromagnetic fields can have both electric and magnetic components.
True
What is a solenoid?
A coil of wire that produces a magnetic field when carrying an electric current.
