#AP Physics 2: Electric Circuits - The Night Before ⚡

Hey there, future physics whiz! Let's get you prepped for the AP Physics 2 exam with a super-focused review of electric circuits. We'll make sure you're not just memorizing, but understanding the flow of electricity. Let's do this!

#Electric Charge and Current

# Definition and Conservation of Electric Charge

Electric charge is the fundamental property that makes matter interact with electromagnetic fields. Think of it as the 'stuff' that feels electrical forces. 💡

• Conservation of Charge: The total charge in a closed system never changes. It can move around, but the overall amount stays the same. This is a cornerstone of circuit analysis. It's like having a fixed amount of water in a closed system; you can move it around, but you can't create or destroy it.

• Charge Carriers: In most circuits, electrons are the primary charge carriers (though we use conventional current which assumes positive charge flow). This is a convention, but it makes everything consistent with electric field direction.

  

  Image: A visual representation of charge conservation in a circuit.

# Current 💨

Current (I) is the rate at which charge flows. It's like measuring how much water flows through a hose per second. The equation is:

$$I = \frac{\Delta Q}{\Delta t}$$

where:

• I is current (Amps, A or milliAmps, mA)
• ΔQ is the charge (Coulombs, C)
• Δt is the time (seconds, s)

• Conventional Current: We use the direction that a positive charge would move, even though electrons (negative) are actually moving. This is just a convention that aligns with electric field direction.

#Drift Velocity

• Drift Velocity (vd): This is the *ave...