AP Physics Electricity & Magnetism

Question 1

What is Ohm's Law?

Accepted Answer

V = I * R

Answer

Ohm's Law is a fundamental principle in electrical circuits that describes the relationship between voltage (V), current (I), and resistance (R). The formula V = I * R states that the voltage across a conductor is directly proportional to the current flowing through it, with the constant of proportionality being the resistance. This law is crucial for analyzing and designing electrical circuits.

Question 2

What does a capacitor do in an electrical circuit?

Accepted Answer

It stores and releases energy

Answer

A capacitor is an electrical component specifically designed to store electrical energy in an electric field between two conductive plates separated by a dielectric material. It can then rapidly release this stored energy back into the circuit, acting like a temporary battery or a filter to smooth out voltage fluctuations. This ability to store and release energy is vital for many electronic applications.

Question 3

How does a magnetic field affect a moving charge?

Accepted Answer

It exerts a force perpendicular to motion

Answer

When a charged particle moves through a magnetic field, it experiences a magnetic force. A key characteristic of this force is that it is always perpendicular to both the direction of the particle's velocity and the direction of the magnetic field. This perpendicular force causes the particle to change its direction of motion, often resulting in a curved path, but does not change its speed.

Question 4

What is the unit of electrical resistance?

Accepted Answer

Ohm

Answer

The Ohm (Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm, who formulated Ohm's Law. Resistance quantifies how much a material opposes the flow of electric current. According to Ohm's Law, one ohm is defined as the resistance between two points of a conductor when a potential difference of one volt produces a current of one ampere.

Question 5

What is the function of an inductor in an electrical circuit?

Accepted Answer

It resists changes in current

Answer

An inductor is a passive electrical component that stores energy in a magnetic field when electric current flows through it. Its primary function is to resist changes in the current flowing through it, a property known as inductance. This resistance to current change helps to smooth out current fluctuations, filter signals, or create specific timing delays in various electrical circuits.

AP Practice Test

AP Practice Test

AP Physics Electricity & Magnetism