EES Mid-semester test

What is Coulombs Law?

Defines the electrostatice force of attraction/repulsion between two charges. F=(q1*q2)/(4*pi*E*r²)

What is charge?

It is a fundamental property of matter making it such that it experiences force when placed in an electromagnetic field/\.

What is electricity?

It is the flow of charged particles

What is current?

It is the flow of charge and is measured in Amperes or Coulombs per second

Equation to measure current

The rate of change of charge flower over time

Equation to measure current (Ohms law)

I=v/r

What is a current sink?

It refers to the maximum current that can flow into an element without it being damaged

What is a current source?

It refers to the maximum current that can flow out of the element before it stops working properly

What is voltage?

It is the work required to move a charge from one point to another

What is electrical potential energy?

It is the energy stored or released when charges are moved within an electric field (Joules)

What is the purpose of a ground?

It is used as a reference point, often it is most helpful when determining voltage as the difference in electrical potential energy is measured from a point to the ground.

What is power?

It is the rate at which energy is absorbed/emitted

What is passive reference configuration?

when the reference direction for current is going into the positive terminal of the reference direction for voltage

What is power if elements are in passive reference configuration?

p = v x i

What is power if elements ARE NOT in passive reference configuration?

p = -v x i

What does it mean if power is positive?

It means the element is absorbing energy from the circuit

what does it mean if power is negative?

it means the element is acting as a source and providing energy into the circuit

what is kirchoff’s current law?

the sum of currents entering any node is zero

what is kirchodd’s voltage law?

the sum of voltages around any loop is zero

What are the properties of elements in series?

One terminal of element A would be connected to one terminal of element B. The current is the same across all elements.

What are the properties of elements in parallel?

The elements would have both their terminals connected to each other (typically through nodes). The voltage is the same across elements.

What is ohm’s law?

V= +- i * R

What is the voltage if the resistor is in passive reference configuration?

V = i x R

What is the voltage if the resistor is not in passive reference configuration?

v = -i x r

What is the equation for the characteristic plot of i versus v in an ideal resistor?

straight line with a slope of 1/R, i= 1/R*V

What is Conductance in relation to resistance?

G=1/R

What is the equation for current with conductance (Ohms Law)?

i = G x v

What is the equation for power with a resistor?

p = v²/R

What is the behavior of resistors?

They are designed to limit current, dissipating energy as heat and hence the element gets hot. Additionally they also introduce a voltage drop.

How can the resistance of a wire be found?

R= resistivity x length / cross sectional area

What is a short circuit?

A circuit with zero resistance and infinite conductance. Voltage across the element is zero regardless of the current flowing through

What is an ideal independent voltage source?

an element that produces voltage across it’s terminals regardless of current

What is an ideal independent current source?

an element that produces current across it’s terminals regardless of voltage

what is an open circuit?

A circuit with zero conductance and infinite resistance. Typically a circuit with zero current regardless of voltage.

What is a VCVS?

A voltage controlled voltage source