Notes, abstracts, papers, exams and problems of Physics

What is the Permeability of a Material and How Does it Differ from Permittivity?

Permeability (µ) measures a material's magnetic response, while permittivity (ε) measures its electric response.

Under What Condition Do Electric and Magnetic Fields Become Coupled?

Electric and magnetic fields become coupled under dynamic conditions, meaning when current, electric field, or magnetic field changes over time.

What Happens to a Waveform's Phasor When Time-Integrated?

When a waveform is time-integrated, its phasor is divided by jω.

Can Phasor Domain Equations Calculate Situations with Signals at Multiple Frequencies?

No, phasor domain equations cannot handle signals at multiple frequencies because they remove time dependence, which must be consistent... Continue reading "Electromagnetism: Key Concepts and FAQs" »

Types of Bias

Bias by omission – leaving one side out of an article, or a series of articles over a period of time; ignoring facts that tend to disprove claims of a group, or that support beliefs by a different group; bias by omission can occur either within a story, or over the long term as a particular news outlet reports one set of events, but not another. 

Bias by selection of sources – including more sources that support one view over another.  This bias can also be seen when a reporter uses such phrases as “experts believe,” “observers say,” or “most people believe.”  Experts in news stories are like expert witnesses in trials.  If you know whether the defense or the prosecution called a particular expert witness to

The first thing I would talk about is the almost repetition of the first and third stanzas. You could argue that Blake shows these two perceptions of love to demonstrate the fine line between love, being controlling and being used by another person.

I like this interpretation. If the clay says love ‘seeketh not to please itself’ and the pebble argues that love ‘seeketh only to please itself’, then they are directly opposed. Does Blake want us to choose? I think not, I think he is really trying to say that we need to avoid viewing love in these terms. Love should be selfish in the respect that we should look to our personal happiness, but at the same time we cannot be selfish and not respect the freedom of those we love.

To further this... Continue reading "Analysis of Love in William Blake's Poem" »

How Did the Universe Start?

The universe is everything that exists. Scientists estimate it could contain 100 billion galaxies. A galaxy is a large group of many stars and celestial bodies.

What Are Stars?

Stars are giant spheres of very hot gas. The Sun is the closest star to Earth.

Constellations

Constellations are visible at different times of the night. We see different constellations in the Northern Hemisphere and the Southern Hemisphere.

Types of Galaxies

Spiral galaxies are disc-shaped, with arms.

Elliptical galaxies are oval-shaped.

Irregular galaxies have no defined shape.

Solar System

Mercury, Venus, Earth, and Mars are inner planets. They are mostly made of rock.

Jupiter, Saturn, Uranus, Neptune, and Pluto are the outer planets. They are mostly... Continue reading "Exploring the Universe: Stars, Galaxies, and the Solar System" »

¡Escribe tu texto aquí!31. Define light Polarization and describe the different types of polarization that we can have.

Polarization of a light ia a process by which an unpolarized light (any light which is having its Vibration in any random direction) is changed to a polarized light (light Having waves vibrating in a particular direction). Polarization is done in Order to produce plane polarized light amd is done by reflection, refraction o Other methods.

Types of polarizaion:

 - Plane polarization.

 - Circular polarization

 - Elliptical polarization

 33- Explain the phenomenon of stimulated Emission and laser operation.

Stimulated Emission is the process by which an incoming photon of a specific frequency can Interact with an excited

Louise Hay born in metz France, to polish-jewish parents. The family immigrated to New York in 1946 after spending part of WW II as refugee in Switzerland. Louise received her B.A in mathematics from Swarthmore College in 1956 and her master's degree from Cornell University in 1959. She then took an instructorship at mount Holyoke College after her husband, whom she had married after her junior year at Swathmore, began a tenure-track position at Smith college.  In 1963 Hay returned to cornell to complete her Ph.D in math, finishing her dissertation in 1965 (after a brief interruption for the birth of twins) . She returned to Mount Holyoke as an assistant professor, the in 1968 after a divorce, movet to the university of illinois at chicago... Continue reading "Louise Hay: Trailblazing Mathematician and Educator" »

b)Explain how elastomers are able to Experience strains of up to 400% when under load and state the importance of the Glass transition temperature.

Answer 5 b)

• Polymers such as rubber – very high strain Capability – in excess of 100%.

• Generally thermoplastics above their Tg – permits Bond rotation.

• Molecules form zig-zag configurations – allows large Amount of stretching - Resistance increases as chains straighten.

• Rubbers have very low ‘E’ values (1 to 20 N/mm2) at Strains up to 400%

• At very high strains a shape change takes place – Provision must be made during use

• Extension or compression results in twisting action At the molecular level

• Above the glass transition temperature (Tg) the Polymer atoms have enough energy to allow this

Tides are the periodic rising and falling of sea levels due to the gravitational pull of the Moon.

When the sea level falls, low tides are created. They occur on the other two opposing sides.

• It has two characteristic movements, revolution and rotation, the same as other celestial bodies.

• Its revolution around the Earth takes 27.32 Earth days. This is the same time it takes the Moon to rotate on its own axis. So, a lunar day is the same length as a lunar year. For this reason, the side of the Moon we see from Earth is always the same.

• The Moon has an average radius of 1738 Km.

• Each year the Moon moves away from our planet