Notes and Study material for Exams
Current Electricity Electric current is the rate of flow of electric charge through a conducting medium with respect to time. It is caused by drift of free electrons through a conductor to a particular direction.Charges in motion constitute an electric current. Such currents occur naturally in many situations. Lightning is one such phenomenon in which … Read more
Magnetic Storm A magnetic storm is a period of rapid Magnetic Field variation. It can last from hours to days. Magnetic storms have two basic causes: The Sun sometimes emits a strong surge of solar wind called a coronal mass ejection. This gust of solar wind disturbs the outer part of the Earth’s magnetic field, … Read more
Magnetic Keepers A magnet keeper, also known historically as an armature, is a ferromagnetic bar made from soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have a low magnetic coercivity, … Read more
Magnetism Magnetism is one aspect of the combined electromagnetic force. It refers to physical phenomena arising from the force caused by magnets, objects that produce fields that attract or repel other objects. All materials experience magnetism, some more strongly than others. Permanent magnets, made from materials such as iron, experience the strongest effects, … Read more
Magnetic keepers A magnet keeper, also known historically as an armature, is a ferromagnetic bar made from soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have a low … Read more
Moving Charge and Magnetism Magnetism is a phenomenon produced by the motion of electric charge, which results in attractive and repulsive forces between objects. A magnet is any piece of material that has the property of attracting iron (or steel). Magnetite, also known as lodestone, is a naturally occurring rock that is a magnet. This … Read more
Most of the knowledge we have about Earth’s deep interior comes from the fact that seismic waves penetrate the Earth and are recorded on the other side. Earthquake ray paths and arrival times are more complex than illustrated in the animations, because velocity in the Earth does not simply increase with depth. Velocities generally … Read more
SDO is a NASA mission launched on February 11, 2010 which will observe the sun for over five years. The observatory is a part of the living with a star program. SDO’s goal is to understand the sun’s influence on earth and near-earth space by studying the solar Atmosphere on small scales of space and … Read more
The following are subtopics of magnetic field: Magnetic field lines Magnetic field strength Magnetic flux Magnetic dipole moment Magnetic field of a current loop Magnetic field of a solenoid Magnetic field of a bar magnet Magnetic field of the Earth Magnetic field of the Sun Magnetic field of stars Magnetic field of galaxies Magnetic field … Read more
Here is a list of subtopics without any description for Sources of the Information about the Interior of Earth: Seismic waves Earth’s Magnetic Field Heat flow Composition of meteorites Composition of volcanic rocks Mantle xenoliths Diamonds Core samples Mineral physics Theoretical models The Earth’s interior is a vast and largely unexplored realm. Scientists have learned … Read more