What are the names and units for; Charge Current Voltage

Charge (q) - coulomb (C) Current (i) - Ampere (A) Voltage (v) - Volt (V)

A current is a….

Coulomb per second

A volt is a…

Joule per coulomb

What’s the charge on an electron?

-1.6x10^-19C

Current(i) = ?

i(t)=dq(t)/dt = Charge/Time

Total charge through a conductor q(t) = ?

q(t) = t(integral)t0 i(t)dt + q(t0)

Voltage is…

The energy transferred per unit charge that flows through the element

A watt is a…

Joule per second

Power =

Voltage x Current

If energy is ____ it is positive but if it is supplied it is ____

If energy is absorbed it is positive but if it is supplied it is negative

Equation to calculate the power delivered to a circuit element between time instants t1 and t2

w = t2(intergral)t1 p(t)dt

The net current entering and leaving a node is?

0

State Kirchoff’s Voltage Law

The algebraic sum of the voltages equals zero for any closed path (loop) in an electrical circuit

In conductors, the voltage between any 2 points of an ____ conductor is ____ regardless of the current

In conductors, the voltage between any 2 points of an ** ideal** conductor is

**regardless of the current**

__zero__When 2 points are connected by an ideal conductor they are ____ together

Shorted

There is an open circuit between two parts of the circuit when?

There are no conductors or other circuit elements connected between 2 parts of a circuit

Dependant voltage sources (also knows as ____ ____ ____) are represented by?

(Controlled voltage sources) Diamond shapes

Resistance = ? and ?

R=V/I and R=(pL)/A

Voltage is ____ to ____ in an ideal resistor

Voltage is proportional to current in an ideal resistor

Typical values of resistivity for Conductors = conductors = Insulators =

Conductors = 10^-8 conductors = 0.1 Insulators = 10^21 (‘infinity’)

Conductance is? and so (Symbol, equation and unit)

G which is 1/R and so Ohms^-1 and so i=Gv

Energy = ? (for a battery)

Q.v

Q = ?

i.T

Energy = ? (2 obvious ones)

mgh and 1/2mv^2

Energy density = ?

Energy (J) / Mass (kg)

Conductances in series and parallel is…?

Opposite to resistance

Voltage divider?

V1 = R1 x i = R1 / (R1+R2+R3) x Vtotal

Fraction of voltage is ratio of…?

Given resistance / total resistance

Fraction of current is ratio of…?

Other resistance / total resistance

For current division - i1 = ? and i2 = ?

i1 = v/R1 = R2/R1+R2 x itotal and i2 = v/R2 = R1/R1+R2 x itotal

The current flowing from node n toward node k is given by…?

(Vn-Vk)/Rx

Avoid writing ____ equations for loops that include ____ sources

Avoid writing KVL equations for loops that include current sources

To ‘zero’ a voltage source you…

Replace it with an short circuit

To ‘zero’ a current source you…

Replace it with an open circuit

The load resistance that maximises the power delivered to the load from a two-terminal circuit is equal to…?

The Thévenin resistance (also called the output resistance) of the circuit

Maximum power results in…?

Plmax = Vt^2/4Rt

iL = ?

iL = Vt/(Rt+RL)

Electrons with never go through a wire with ____, it will always go the ____ ____

Electrons will never go through a wire with resistance, it will always go the other way

Anything in parallel with a empty wire makes…?

0V

The total response is…

The sum of the responses to each of the independent sources acting individually

A resistance that obeys Ohm’s law is…?

Linear

What only applies to linear circuits?

Superposition

What is used to measure unknown resistances?

The Wheatstone bridge

When is the Wheatstone bridge balanced?

when ig = 0 and Vab = 0

For the Wheatstone bridge, Rx = ?

Rx = (R2/R1)R3