Physics Test 2 - Definitions

Front 1

emf

Back 1

the work done per unit charge

SI unit: Volt or J/C

m2 · kg · s-3 · A-1

Front 2

E is equal to the ______ _______ when the current is zero

Back 2

terminal voltage

AKA open-circuit voltage

Front 3

load resistance

Back 3

Terminal voltage must also equal the potential difference across the external resistance.

E = IR + Ir

Front 4

I = E/R+r

Back 4

shows that the current depends on:
-External resistance
-Internal resistance

Front 5

If R is much greater than r

Back 5

We can neglect r in our analysis

Assume that r is negligible

Front 6

IE = I^2R + I^2r

Back 6

Tells us that the total power output IE is converted to the rate I^2 at which energy is delivered to the load resistance plus the rate I^2r at which energy is delivered to the internal resistance.

Front 7

emf

Back 7

the source that maintains the current in a closed circuit.

Front 8

steady state

Back 8

assumed that most currents are constant in magnitude and direction.

Front 9

Any device that increase the ____ ______ of charges circulating in circuits are sources of emf

Back 9

potential energy.

Front 10

Think of a source as a ____ ____.

Back 10

Charge pump.

Forces electrons to move in opposite direction of electrostatic field inside the source.