Electricity Archives - Fridge Physics

Electricity

Charge

The size of the current is the rate of flow of charge. Electrons are negatively charged particles which transfer energy through wires as electricity.

What is Charge?

The size of the current is the rate of flow of charge. Electrons are negatively charged particles which transfer energy through wires as electricity. Charge is measured in coulombs (C). Electrons are really small and the effect of one electron would be really difficult to measure, It is easier to measure the effect of a large number of electrons. One Coulomb of charge contains 6 Ã— 1018 electrons.

Charge equation

To calculate Charge we use this equation.

$Q = { \mathit I \, \mathit t} $

Charge demo

In this tutorial you will learn how to calculate the the charge flowing in an electrical circuit.

Chilled practice question

Calculate the charge when a current of 16 A flows for 2 minutes.

Frozen practice question

How long must a current of 26 A flow to transfer 936 KC.

Science in context

The size of the current is the rate of flow of charge.

Millie’s Master Methods

The Fridge Physics Store

Resistance

Resistance is an electrical quantity that measures how a device or material reduces the electrical current flow through it.

What is Resistance?

Resistance is an electrical quantity that measures how the device or material reduces the electrical current flow through it. Resistance is measured in ohms (Ω).If we make a comparison of resistance to water flow in pipes, the resistance is greater when the pipe is thinner, so the water flow is decreased It slows down which also happens to the flow of electricity.

Resistance equation

To calculate Resistance we write the equation like this.

$V = { \mathit I \, \mathit R} $

Resistance demo

In this tutorial you will learn how to calculate the resistance in an electrical circuit.

Chilled practice question

Calculate the resistance of a bulb supplied with 8 V and a current flow of 2 A.

Frozen practice question

Calculate the current in a circuit which has a resistance of 16 Ω and a potential difference of 8 V.

Science in context

Resistance reduces the flow of electricity.

Millie’s Master Methods

The Fridge Physics Store

Resistance in Series and Parallel

Resistors in series and in parallel can change the total resistance in a circuit.

What is Resistance in series and parallel?

Resistors in series and in parallel change the total resistance in a circuit. Special components called resistors are made especially for creating a precise quantity of resistance in a circuit. They are generally made of metal wire or carbon and constructed to maintain a stable steady amount of resistance over a wide range of environmental conditions.

Resistance in series and parallel equation

To calculate Resistance in series we use this equation.

$R_t = {\mathit R_1 \text + \mathit R_2}$

Resistance in series and parallel demo

In this tutorial you will learn how to calculate the total resistance of resistors in series and parallel.

Chilled practice question

Calculate the current in a circuit if it is supplied with a voltage of 36 V and has two resistors in series one 6 Ω and the other 3 Ω.

Frozen practice question

Three resistors are connected in parallel, resistor A is 2 Ω , resistor B is 4 Ω, and resistor C is 5 Ω . What is the total resistance in the circuit ?

Science in context

Resistance in series and parallel change the total resistance in a circuit

Millie’s Master Methods

The Fridge Physics Store

Electrical Power

The power of an appliance is the energy that is transferred per second. Electric power is the rate, per unit time at which electrical energy is transferred by an electric circuit.

What is Electrical power?

The power of an appliance is the energy that is transferred per second. Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The unit for power is the watt, which is the transfer of energy at the rate of one joule per second. Electric power can be produced by electric generators and batteries.

Electrical power equation

To calculate Electrical power we use this equation.

$ {\mathit P \, \text = \mathit V \mathit I}$

Electrical power demo

In this tutorial you will learn how to calculate the electrical power of an electrical appliance.

Chilled practice question

Calculate the power in a circuit when a p.d of 18 V and a current of 4 A is measured.

Frozen practice question

Find the current flowing through an appliance which has a power rating of 14 KW and a p.d of 230 V.

Science in context

The power of an appliance is the energy that is transferred per second

Millie’s Master Methods

The Fridge Physics Store

Energy Transformed

The potential difference between two points is the energy transferred per unit charge. An electrical circuit is an energy transformation device.

What is Energy transformed?

The potential difference between two points is the energy transferred per unit charge. An electrical circuit is an energy transformation device. Energy is provided to the circuit by an electrochemical cell, battery, generator or another electrical energy source. Energy is delivered by the circuit. The rate at which this energy transformation takes place has a great relevance to the design of an electrical circuit for useful functions.

Energy transformed equation

To calculate Energy transformed we use this equation.

Energy = power x time

$ {\mathit E \, \text = \mathit P \mathit t}$

Energy = charge flow x potential difference

$ {\mathit E \, \text = \mathit Q \mathit V}$

Energy transformed demo

In this tutorial you will learn how to calculate the energy transformed through an electrical circuit.

Chilled practice question

Calculate the energy transformed if a circuit is supplied with 6 V and 32 C of charge flows.

Frozen practice question

Calculate the energy transformed when a current of 4 A flows with a p.d of 230 V for 18 s.

Science in context

The potential difference between two points is the energy transferred per unit charge

Millie’s Master Methods

The Fridge Physics Store

Transformers

A transformer is an piece of electrical apparatus which will increase or decrease the voltage in an alternating current. It can be designed to “step up” or “step down” voltages and is based on the magnetic induction principle.

Demo

In this tutorial you will learn how to calculate voltages in step up and step down transformers.

The equation is written like this:

${ \text V_{1} \; \text / \; \text V_{2} \; \text = \; \text N_{1} \; \text / \; \text N_{2} \;}$

Chilled practice question

A transformer has 300 turns on its primary coil and 100 turns on it secondary coil. What voltage is induced in the secondary coil if the primary voltage is 96 V ?

Frozen practice question

A transformer has 320 turns on the primary coil and 800 turns on the secondary coil. Find the voltage across the primary coil when the voltage across the secondary coil is 1320 V.

Science in context

A transformer is an piece of electrical apparatus which will increase or decrease the voltage in an alternating current. It can be designed to “step up” or “step down” voltages and is based on the magnetic induction principle.When a voltage is introduced to one coil, called the primary coil it magnetizes its core which is made from iron which induces a voltage in the secondary coil.

Millie’s Master Methods

The Fridge Physics Store

The Motor Effect

A current-carrying wire or coil can exert a force on a permanent magnet. The force increases if the strength of the magnetic field and/or current increases. This is called the motor effect.

Demo

In this tutorial you will learn how to calculate the force on a wire carrying a current in a magnetic field.

The equation is written like this:

$F = { \text B \; \text x \; \text I \; \text x \; \text L}$

Chilled practice question

Calculate the force on a wire carrying a current of 3 A. 0.25 m of the wire is in the magnetic field. The magnetic flux density is 15 T.

Frozen practice question

The force on a wire in a magnetic field is 30 N. The magnetic flux density is 3 T and the length of wire in the magnetic field is 50 cm. Calculate the current.

Science in context

A current-carrying wire or coil can exert a force on a permanent magnet.The force increases if the strength of the magnetic field and/or current increases. This is called the motor effect.

Millie’s Master Methods

The Fridge Physics Store

Scroll to Top