Science exam 2 Flashcards
must know by Thursday
Definition of voltage
Voltage is the pressure from an electrical circuit’s power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating a light.
Definition of current
Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms.
Definition of resistance
is a measure of how difficult it is for current to flow.
Definition of Potential difference
Another name for voltage, the difference in electric potential between two points in a circuit.
difference between series and parallel circuits
In a series circuit, the total voltage from the battery is divided between the components. For example, if you have a 6V battery and two lamps, each lamp might get 3V.
In a parallel circuit, each component gets the full voltage from the battery. So if you have a 6V battery, each lamp gets 6V.
series circuit
A series circuit is a type of electrical circuit where all components are connected in a single path, the same current flows through each component the voltage is split between the components . If one part of the circuit breaks, the entire circuit stops working.
parallel circuit
A parallel circuit is an electrical circuit where components are connected in multiple paths, the current can flow through more than one path. Each component receives the full voltage from the power source, and if one path is broken, the other paths can still function.
ohms law
formular:
V= Voltage
I= Current
R= Resistance
V= I x R
I= V divide R
R= V divide I
Light waves
Light Waves: Light waves are transverse waves, meaning they oscillate perpendicular to the direction of travel.
How light waves are measured
Measurement: Wavelength and frequency are used to measure light waves.
Speed of light in a vacuum
Speed of Light: The speed of light in a vacuum is approximately
3×100000000
3×10 8
meters per second.
light made of particles
Light is also made up of particles called photons.
terms associated with reflection of light.
Reflection Terms: Angle of incidence, angle of reflection, normal, incident ray, reflected ray.
The relationship between the angle of incidence and the angle of reflection.
Law of Reflection: The angle of incidence i
i is equal to the angle of reflection r
refraction
Refraction: The bending of light as it passes from one medium to another due to a change in speed.
why objects look distorted or closer when light is refracted through a medium such as water.
Distortion: Objects look distorted or closer in water because light slows down and bends when it enters a denser medium, like water, changing the perceived position of the object.
Define refractive index and how it applies to bending of light.
Refractive Index: A measure of how much light slows down and bends when entering a medium. It is calculated by the ratio of the speed of light in a vacuum to the speed of light in the medium.
Identify the primary and secondary colors of light.
Primary Colors: Red, Green, Blue (RGB).
Secondary Colors: Cyan, Magenta, Yellow (formed by mixing primary colors).
Understand how colors in white light are reflected (or absorbed) in opaque objects.
Reflection/Absorption: Opaque objects reflect certain wavelengths (colors) of light and absorb others. The color you see is the color of light reflected.
Optic fibres and how they work
Optic fibers are thin strands of glass or plastic used to transmit data as light signals. They work through a process called total internal reflection, where light continuously bounces off the walls of the fiber, allowing data to travel quickly over long distances with minimal signal loss.
how do microwave ovens work
Microwave ovens work by generating electromagnetic waves that cause water molecules in food to vibrate, producing heat through friction that cooks the food from the inside out.
the benefits of optic fibers over conventional wires in communication systems.
Benefits of Optic Fibers: Higher bandwidth, faster data transmission, and less signal degradation compared to conventional wires.
definition of transparent
A material that allows light to pass through it so that objects behind can be clearly seen (e.g., glass).
definition of Translucent
A material that allows some light to pass through, but not enough to see through it clearly (e.g., frosted glass).
definition of Opaque
A material that does not allow light to pass through it (e.g., wood).
Law of Reflection
The angle of incidence (
i
i) is equal to the angle of reflection (
r
r).
Speed in vacuum over speed in medium
n = c over v
N is the refractive index
C is the speed of light in a vacuum
V is the speed of light in a medium
What are the advantages of optic fibres
High data transmission
Less signal loss
Immunity to electromagnetic wave
