Energy and Electricity pt.2 Flashcards
What is energy?
Energy is the ability to do work or cause change.
What are the main types of energy?
Kinetic energy: Energy of motion.
Potential energy: Stored energy.
Thermal energy: Energy due to the motion of particles (heat).
Chemical energy: Energy stored in chemical bonds.
Electrical energy: Energy from moving electrons.
Nuclear energy: Energy stored in the nucleus of an atom.
Light energy (radiant): Electromagnetic energy visible as light.
What is the difference between energy transfer and energy transformation?
Energy transfer: Energy moves from one object to another without changing form (e.g., heat from a stove to a pot).
Energy transformation: Energy changes from one form to another (e.g., electrical energy into light energy in a bulb).
What is wasted energy?
Energy that is not useful and is dissipated into the surroundings, often as heat or sound.
What is energy efficiency, and how is it calculated?
Energy efficiency measures how much useful energy is produced compared to the total energy input.
Efficiency = (Useful energy output / Total energy input) × 100%
What is the Law of Conservation of Energy?
Energy cannot be created or destroyed; it can only be transferred or transformed.
Give an example of energy transformation in a toaster.
Electrical energy → Heat energy (useful) + Sound energy (wasted).
What is voltage?
Voltage is the measure of electrical energy carried by charges in a circuit, measured in volts (V).
What is current?
Current is the flow of electric charge through a circuit, measured in amperes (A).
What is resistance, and how is it measured?
Resistance is the opposition to the flow of current in a circuit, measured in ohms (Ω).
State Ohm’s Law.
Ohm’s Law describes the relationship between voltage, current, and resistance:
V = IR
What happens to current if resistance increases while voltage stays the same?
The current decreases because current and resistance are inversely proportional.
What is a circuit?
A circuit is a closed loop that allows electric current to flow.
What is the difference between a series and a parallel circuit?
Series circuit: Components are connected in a single path; the same current flows through all components.
Parallel circuit: Components are connected across multiple paths; the voltage is the same across each branch, and current is divided.
What are the advantages of parallel circuits over series circuits?
If one component fails, others continue to work.
Each branch gets the full voltage of the power source.
Components can operate independently.
What is electrical power, and how is it calculated?
Electrical power is the rate at which electrical energy is converted into other forms of energy.
P = VI
What are conductors and insulators?
Conductors: Materials that allow electricity to flow easily (e.g., copper, aluminum).
Insulators: Materials that resist the flow of electricity (e.g., rubber, plastic).
What is the purpose of a fuse in a circuit?
A fuse protects circuits by breaking the connection if the current exceeds a safe level, preventing overheating or damage.
What are some examples of renewable and non-renewable energy sources?
Renewable: Solar, wind, hydroelectric, geothermal, biomass.
Non-renewable: Coal, oil, natural gas, nuclear.
What is the function of a transformer in electricity transmission?
A transformer changes the voltage of electricity:
Step-up transformers increase voltage for efficient long-distance transmission.
Step-down transformers decrease voltage for safe use in homes.
