Electromagnetism
What are the parts of an atom and their respective charges?
Protons (+), Neutrons (0), and Electrons (-).
What is the amplitude of a wave?
The amplitude is the height of the wave from the rest position to the crest or trough.
What happens to light when it encounters a transparent material?
It passes through with little to no scattering.
What is the difference between rotation and revolution in the context of the Earth?
Rotation is the spinning of the Earth on its axis, which causes day and night. Revolution is the orbit of the Earth around the Sun, which takes one year.
What type of circuit allows a current to flow through it?
A closed circuit.
How do like charges and unlike charges interact with each other?
Like charges repel each other, while unlike charges attract each other.
How does the energy of a wave relate to its amplitude?
The energy of a wave is proportional to the square of its amplitude.
Describe a concave mirror and how it affects light.
A concave mirror curves inward like a bowl and can focus light to a point.
How does the tilt of the Earth's axis affect the seasons?
The tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, creating seasons.
What is an electromagnet, and why are they useful?
An electromagnet is a type of magnet created by an electric current. They are useful because their magnetism can be turned on and off and their strength can be adjusted.
What is an electric field, and what factors determine its strength?
An electric field is a region around a charged object where the object's electric force is exerted on other charges. The strength is determined by the amount of charge and the distance from the charge.
If one wave has an amplitude of 2 meters and another has an amplitude of 6 meters, how much greater is the energy of the second wave?
The second wave has 9 times more energy than the first wave (since energy ∝ amplitude^2).
What kind of surface causes a regular reflection versus a diffused reflection?
A smooth surface causes a regular reflection, while a rough surface causes a diffused reflection.
What are solstices and equinoxes, and when do they occur?
Solstices are the points when the Sun is at its greatest distance from the equator, occurring around June 21 and December 21. Equinoxes are when the Sun is directly above the equator, occurring around March 21 and September 23.
What is the law of reflection?
The law of reflection states that the angle of incidence (the angle at which incoming light rays strike a surface) is equal to the angle of reflection (the angle at which light rays bounce off the surface).
How can you make a temporary magnet, and what is the difference between a temporary and a permanent magnet?
A temporary magnet can be made by stroking a piece of iron with a magnet or by passing an electric current through a wire wrapped around it. Temporary magnets lose their magnetism quickly, while permanent magnets retain their magnetism.
What is the relationship between wavelength and frequency in a wave?
Longer wavelengths correspond to lower frequencies, and shorter wavelengths correspond to higher frequencies.
What is refraction and when does it occur?
Refraction is the bending of light as it passes from one medium to another.
Describe what happens during a solar eclipse and during which moon phase it occurs.
A solar eclipse occurs when the Moon passes between the Earth and the Sun, blocking the Sun's light. It occurs during the new moon phase.
Eclipses occur only when the three bodies align in a straight line. For a solar eclipse, the Moon must be between the Earth and the Sun, and for a lunar eclipse, the Earth must be between the Sun and the Moon. The tilt of the Earth's axis relative to its orbit causes these alignments to be infrequent, as the Moon's orbit is tilted about 5 degrees relative to the Earth's orbit around the Sun.
Describe three ways to increase the strength of an electromagnet.
Increase the number of coils in the wire, increase the electric current passing through the wire, and use a stronger ferromagnetic core.
How do mechanical waves interact with different materials? Name and describe three types of interactions.
Transmission (waves pass through a material), reflection (waves bounce off a surface), and absorption (waves are absorbed by a material and converted to other forms of energy).
Which mirror/lens produces a real image?
Concave mirror and convex lens.
Explain why lunar eclipses can be seen from anywhere on the night side of Earth but solar eclipses are only visible from specific locations.
Lunar eclipses occur when the Earth casts a shadow on the Moon, which can be seen by anyone on the nighttime side of the Earth. Solar eclipses are when the Moon's shadow falls on the Earth, and only those in the narrow path of the shadow can see it.
What moon phase will occur three weeks after a new moon?