Higher Physics: Unit 3 - Electricity

What is alternating current?

Current that changes direction

What is peak voltage?

Maximum voltage achieved by a signal

What is used to obtain the peak voltage?

An oscilloscope

In terms of peak voltage, what did the y-gain tell us?

Voltage represented by each box

How to calculate peak voltage from a graph

Count the number of boxes from O to a peak then multiply by the Y-Gain

What is used to obtain the frequency of a signal?

An oscilloscope

In a series circuit, Current is…

Constant

In a series circuit, voltage is….

Split up across the components

In a series circuit, total resistance is…

individual resistances added together

In a parallel circuit, current is…

Split up across the components

In a parallel circuit, voltage is…

Constant

In parallel circuit, total resistance is…

1 divided by each resistance added together and flipped

What is the r.m.s voltage?

The value of direct voltage that produces the same power as the alternating voltage.

What does a potential divider do?

Divides voltage within a current so parts of the circuit only receive the voltage they require.

What is resistance?

a measure of how difficult it is for an electric current to pass through a component

What is current?

Number of charges passing a point per second

What is voltage?

Energy per coulomb of charge

What is potential difference?

voltage

What is power?

Energy consumed per second

What is charge?

Value for electricity flowing in a circuit

What is EMF?

The energy given to each coulomb of charge that passes through the source

What is internal resistance?

The resistance inside the battery/cell/power supply caused by the electrons colliding with atoms inside the device.

What are lost volts?

The energy wasted per coulomb overcoming the internal resistance.

What is terminal potential difference?

The potential difference across the load resistance

What is a capacitor?

a component that stores charge

What is capacitance?

ability to store charge

What is the gap between the plates of a capacitor called?

Insulator

When a capacitor is uncharged, what is the voltage equal to?

0

When a capacitor is fully charged, the voltage across it is equal to….

The supply voltage

When a capacitor is fully charged, the current is equal to….

0

How easily charges can flow through the material

What are conductors?

Materials with high conductivity

What are insulators?

Materials with low conductivity

What are semiconductors?

Materials that can act as either conductors or insulators

What is a valence band?

Outermost energy band of an atom where electrons can jump out of

What is a conduction band?

The band where electrons are free to move in the material, creating an electrical current

What is band gap?

Space between valence and conduction band

What does a large band gap mean?

Lots of energy is required for electrons to move to conduction band

What is the fermi level?

The top of the collection of electron energy levels at Absolute Zero

What is absolute zero?

0 Kelvin

What does a small band gap mean?

Small amounts of energy is required for electrons to move to the conduction band