Notes and Study material for Exams
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
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
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
The Earth’s Magnetic Shield: A Journey into Geomagnetism The Earth, our home planet, is not just a rocky sphere floating in space. It possesses a hidden, yet vital, force field: the geomagnetic field. This invisible shield, generated deep within the Earth’s core, protects us from the relentless barrage of charged particles emanating from the Sun, … Read more
Unlocking Earth’s Secrets: A Journey Through Paleomagnetism The Earth, a dynamic and ever-changing planet, holds within its very core a fascinating story of its past. This story, etched in the magnetic field that surrounds our planet, can be deciphered through the study of paleomagnetism, a powerful tool that allows us to unravel the mysteries of … Read more
The Invisible Force: A Deep Dive into Magnetic Fields The world around us is teeming with unseen forces, shaping everything from the movement of celestial bodies to the functioning of our everyday devices. One such force, often overlooked but undeniably powerful, is the magnetic field. This article delves into the fascinating world of magnetic fields, … 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
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 … 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