AP Physics C E&M Review

Front

What is the magnetic field produced by a long, hollow, thin-walled conducting cylindrical shell carrying a current?

Back

The magnetic field inside the shell is zero, and outside it decreases with distance from the shell according to the formula B = (μ₀I)/(2πr), where I is the current and r is the distance from the axis.

Front

What is the electric potential energy of a system of charges?

Back

The electric potential energy is the work done to assemble the charges from infinity. It is not zero when a third charge is placed between two equal positive charges, as it experiences a net force.

Front

How does the electric field strength vary with distance from a line of charge?

Back

The electric field strength (E) from an infinite line of charge is given by E = (λ)/(2πε₀r), where λ is the linear charge density and r is the distance from the line. It is inversely proportional to the distance.

Front

What is the principle of superposition in electric fields?

Back

The principle of superposition states that the total electric field created by multiple charges is the vector sum of the electric fields created by each charge individually.

Front

What is the formula for the electric field due to a point charge?

Back

The electric field (E) due to a point charge (Q) is given by E = k|Q|/r², where k is Coulomb's constant and r is the distance from the charge.

Front

What happens to the electric field strength when the distance from a point charge is halved?

Back

The electric field strength increases by a factor of four, as it is inversely proportional to the square of the distance (E ∝ 1/r²).

Front

What is the direction of the electric field created by a positive charge?

Back

The electric field lines radiate outward from a positive charge, indicating that a positive test charge would move away from it.

Front

What is the electric field at a point due to two equal and opposite charges?

Back

At a point equidistant from two equal and opposite charges, the electric field is directed towards the negative charge, as the fields from both charges add vectorially.

Front

How do you determine the net electric field at a point due to multiple charges?

Back

To find the net electric field, calculate the electric field due to each charge at that point and then vectorially add them together.

Front

What is the relationship between electric potential and electric field?

Back

Electric potential (V) is related to electric field (E) by the equation E = -dV/dr, indicating that the electric field is the negative gradient of the electric potential.