Voltage, current, and phase angle. In general, the instantaneous voltage between two points in an ac circuit is not in phase with the instantaneous current passing through those points.

Resistance and reactance. The voltage across a resistor is in phase with the current, . The voltage across an inductor leads the the current by , , inductive reactance . The voltage across a capacitor lags the the current by , , capacitive reactance .

Impedance and the L-R-C series circuit. In general ac circuit, the voltage and current amplitutes are related by the circuit impedance , . In an L-R-C series circuit, , .

Power in ac circuits. The average power input to an ac circuit: , where is the phase angle of the voltage relative to the current. The factor is called the power factor of the circuit.

Mutual inductance. When a changing current in one circuit causes a changing magnetic flux in a second circuit, an emf is induced in the second circuit. and , – mutual inductance, – number of turns of coil of the first circuit, – average magnetic flux through each turn of coil 1.

Self-inductance. A changing current in any circuit causes a self-induced emf , – depends on the geometry of the circuit and the material surrounding it.

Magnetic field energy. An inductor with inductance carrying current has energy associated with the inductor’s magnetic field: . Magnetic energy density: .

R-L circuits. In an R-L circuit the growth and decay of current are exponential with time constant .

L-C circuits. An L-C circuit undergoes electrical oscillations with an angular frequency .

L-R-C circuits. The frequency of damped oscillations .

No proverbial zombies or substances this time. Deeper and more likeable characters, who you actually care about – nothing like “The Last of Us” with its “emotional bond development” crap. Way better from moral standpoint. A lot (a lot!) of details. Very impressive facial expressions. A real treat for vehicle driving fans. Incredibly small number of bugs. I didn’t feel irritated with the gamepad while shooting (like I did playing Uncharted 1-3).

The biggest con I can think of is the traditional (for the Uncharted series) total lack of (perceived) cooperation among opposing NPCs. Of course, if one of the NPCs sees you, a bunch of others will attack you as well, but they won’t say anything – as if they just communicate telepathically. Probably a design choice, because there’s already a lot of comments and remarks going on between the player and his allies.

Also, I didn’t particularly like the two ending scenes. The thing is, all the three Drakes – who we meet in the game (Elena is somehow sill Fischer) – lie to each other, to Elena, and to others, at one point of the game or another. And only Nathan has to pay for it, and only a little. And the only guy in the whole game who is actively, seriously not happy about lying is… the villain! Who dies in a deus-ex-machina way – as usual in the Uncharted series.

P.S. How come Rafe didn’t see Sam at Rossi???

P.P.S. Actually, that’s not the only curious thing about the game.

Faraday’s law. Induced emf in a closed loop , – magnetic flux through the loop.

Lenz’s law. An induced current or emf always tends to oppose or cancel out the change that caused it.

Motional emf. .

Induced electric fields. When an emf is induced by a changing magnetic flux through a stationary conductor, there is an induced nonconservative electric field : .

Displacement current. A time-varying electric electric field generates displacement current , which acts as a source of magnetic field in exactly the same way as conduction current: .

Maxwell’s equations. The relationships between electric and magnetic fields and their sources:

(Gauss’s law for fields)
(Gauss’s law for fields)
(Faraday’s law)
(Ampere’s law including displacement current).