Electric Potential, Ohm's Law, Inductance & Electromagnetic Induction (Video Notes Review)

Fill-in-the-blank flashcards covering electric potential, Ohm's law, resistivity, current density, inductance, Faraday's law, transformers, and related electromagnetic concepts from the video notes.

The electrical potential difference VB - VA is defined as the work done per unit charge in carrying a positive test charge from A to B, i.e., VB - VA = __.

W/q

The electrostatic force between a stationary point charge +Q and a test charge q separated by a distance r is F = __.

k Q q / r^2

The potential difference VA - VB between A and B due to a point charge Q is VA - VB = __.

k Q (1/rA - 1/rB)

If the reference potential is chosen to be zero at infinity and B is at infinity, the electric potential at A is VA = ___.

k Q / r_A

The unit of electric potential is the volt, where 1 V = __.

1 J/C

Ampere's circuital law states that the line integral around a closed path of the magnetic field H equals the __ enclosed.

I_enclosed

Ohm's law is V = __.

I R

The resistance of a conductor is R = ρ L / A; here ρ is the __.

resistivity

The temperature dependence of resistance is R = R0 [1 + α (T − T0)], where α is the __ of resistance.

temperature coefficient of resistance

The current density J is defined as J = I / __.

A

The units of the current density J are __.

A/m^2

The elementary charge e has magnitude e = __ C.

1.6 x 10^-19 C

The average drift velocity vd of electrons is the response to the applied ___.

electric field

The induced emf in Faraday's law is ε = __.

• dΦ/dt

For N turns, the flux linkage is Φm = ___.

N B A cos θ

The inductance L is the flux linkage per __.

unit current

The energy stored in an inductor when the current rises to I is U = __.

(1/2) L I^2

The magnetic energy density in a magnetic field is u = __.

B^2/(2 μ0)

In a long solenoid, the magnetic field inside is B = __.

μ0 n I

In an ideal transformer, the voltages satisfy Vp / Vs = __.

Np / Ns

The SI unit of mutual inductance is the __.

Henry (H)

One henry equals one weber per ampere: 1 H = __.

1 Wb/A

The emf at the brushes of a DC generator is __.

unidirectional