Idk Flashcards
Define electrochemical cells
Convert chemical energy into electric energy
Electrochemical cells are devices that generate electric energy through chemical reactions.
What are electrochemical cells commonly called?
Batteries
Batteries are a type of electrochemical cell that store and provide electrical energy.
What is the purpose of electrochemical cells?
Store portable energy
Electrochemical cells are used in various applications to provide energy where needed.
Label the following diagram components of an electrochemical cell: _______
carbon rod, negative terminal, electrolyte/paste, plastic insulator, positive terminal, lead plate
These components are essential for the functioning of an electrochemical cell.
What are the two terminals of a battery called?
Positive and negative
These terminals are also referred to as electrodes.
What are electrodes made of?
Two different types of metal: zinc and copper
The specific metals used can vary depending on the battery type.
What surrounds the electrodes in a battery?
An electrolyte
The electrolyte is a substance that conducts electricity.
What happens to the copper electrode when a battery is in use?
It becomes positively charged
This occurs due to chemical reactions that pull electrons off the copper electrode.
When there is a completed circuit, where do the electrons flow from?
From the negative terminal towards the positive terminal
Give examples of objects that use dry cells.
Laptop, battery
Dry cells are commonly used in portable electronic devices.
What is the electrolyte in a dry cell?
A moist, dark substance
Give examples of objects that use wet cells.
Car batteries
Wet cells are often used in larger applications like vehicles.
What is the electrolyte in a wet cell?
A liquid solution
Define energy.
The ability to do work
In what units is energy measured?
Joules (J)
What is the difference between kinetic and potential energy?
Kinetic Energy: energy in motion; Potential Energy: energy that’s stored
Define electric potential energy.
Electric energy stored
What is the amount of electric potential energy per one coulomb called?
Potential difference
What instrument is used to measure potential difference?
Voltmeter
What are the units of measurement for potential difference?
Volts (V)
Define electric circuit
A complete pathway that allows electric current to flow.
This includes a source, load, and conductors.
Define electric load
Anything connected to the circuit.
This can include devices like light bulbs or motors.
What are the four components of a circuit?
- Source
- Conductor
- Load
- Switch
Each component plays a critical role in the functioning of the circuit.
What is an example of a source in an electric circuit?
Battery
A source provides the voltage needed for current to flow.
What is an example of a conductor in an electric circuit?
Metal wires or water
Conductors allow the flow of electric current through the circuit.
What is the function of a switch in a circuit?
A device that opens or closes a circuit, turning it on or off.
Switches can control the flow of electricity in a circuit.
What is a circuit diagram?
A picture that represents an actual circuit, using symbols to show how the circuit is connected.
Circuit diagrams are essential for understanding and building circuits.
Current is defined as the amount of charge passing a point in a conductor every second. It is measured in _______.
Amperes (A)
Current is a fundamental electrical quantity.
An _______ is a device used to measure the current in a circuit.
Ammeter
Ammeters are connected in series with the circuit.
Convert the following units: 1A = _______ mA.
1000 mA
1 Ampere is equal to 1000 milliamperes.
Which way do electrons flow in a circuit?
From negative electrode towards the positive electrode
This is the actual direction of electron flow.
How is this different from conventional current?
Conventional current flows in the opposite direction
Conventional current is defined as flowing from positive to negative.
Define resistance.
How much material opposes the flow of current
Resistance is a measure of the difficulty for current to flow.
Define resistor.
Component which limits the flow of current
Resistors are used to control voltage and current in circuits.
What will happen to the current of a circuit if the voltage is increased?
The current will increase
This relationship is described by Ohm’s Law.
Draw a sketch of a graph of how current changes with voltage (label both axes).
Current on the y-axis, Voltage on the x-axis
The graph typically shows a linear relationship, indicating that current increases with voltage.
What does the symbol R represent in Ohm’s Law?
Resistance
Units: Ohms (Ω)
What does the symbol V represent in Ohm’s Law?
Voltage
Units: Volts (V)
What does the symbol I represent in Ohm’s Law?
Current
Units: Amperes (A)
How do you convert 1 mA to A?
1 mA = 0.001 A
1 mA is equal to one thousandth of an Ampere.
Convert 12.0 mA to A.
0.012 A
12.0 mA = 12.0 / 1000 A
Convert 0.075 A to mA.
75 mA
0.075 A = 0.075 * 1000 mA
How do you convert 1 kΩ to Ω?
1 kΩ = 1000 Ω
kΩ represents kiloohms.
Convert 3.0 kΩ to Ω.
3000 Ω
3.0 kΩ = 3.0 * 1000 Ω
How do you convert 1 MV to V?
1 MV = 1,000,000 V
MV represents megavolts.
Convert 14 MV to V.
14,000,000 V
14 MV = 14 * 1,000,000 V
Using Ohm’s Law, what is the formula for calculating resistance?
R = V / I
Where R is resistance, V is voltage, and I is current.
What resistance (R) would produce a current of 20 A with a potential difference of 240 volts (V)?
12 Ω
R = 240 V / 20 A = 12 Ω
If a 9 V battery produces a current of 25 mA, what is the resistance?
360 Ω
R = 9 V / 0.025 A = 360 Ω
What is a short circuit?
A condition where electricity flows along an unintended path, causing excessive current.
Short circuits can lead to overheating and potential fire hazards.
How do electrons move through a circuit powered by direct current?
Electrons flow from the negative terminal to the positive terminal of the battery in a unidirectional manner.
Direct current (DC) maintains a constant voltage and current direction.
Give examples of devices using direct current.
- Battery-powered devices
- Electronic circuits
- Solar panels
- Small appliances
What is an example of a short circuit?
A wire touching another wire or conductive material unintentionally, bypassing the load in the circuit.
This can cause a surge in current flow.
How do electrons move through a circuit powered by alternating current?
Electrons periodically reverse direction, oscillating back and forth.
Alternating current (AC) changes its polarity at regular intervals.
Give examples of devices using alternating current.
- Household appliances
- Microwave ovens
- Electric heaters
- Large electrical machines
Why is electricity dangerous?
It can disrupt normal healthy functioning of the body, particularly affecting the heart and nervous system.
Electric shock can cause cardiac arrest and other severe injuries.
What is more dangerous, the current or the voltage?
Current is more dangerous because it is the flow of electricity that can cause harm to the body.
High voltage can lead to high current flow, but it is the current that directly affects bodily functions.
