Step-Up & Step-Down Transformers A transformer is A device that changes high alternating voltage at low current to low alternating voltage at high current, and vice versa This is designed to re...
Root-Mean-Square Current & Voltage Direct current sources provide a constant voltage and current over time, making it easy to measure In situations involving alternating voltage and current, th...
AC Generators If a coil of wire is rotated inside a magnetic field by an external force, an emf will be generated in the wire which causes current to flow within the coil The?generator effect?can b...
Lenz's Law Lenz’s Law is used to predict the?direction?of an induced e.m.f in a coil or wire Lenz's Law is summarised below: The induced e.m.f is set up in a direction to produce effects that oppos...
Induced Emf Electromagnetic induction is a phenomenon which occurs when an?e.m.f.?is induced when a conductor moves through a magnetic field When the conductor cuts through the magnetic field lines...
Emf, Magnetic Flux & Magnetic Flux Linkage Electromagnetic Induction When a conducting wire moves through a magnetic field, a?potential difference?is created along the wire If the wire is part ...
Forces on Charges & Masses The electric field strength equation can be rearranged for the force?F?on a charge?Q?in an electric field?E: Where: F = electrostatic force on the charge (N) Q = char...
Forces & Inverse-Square Law Behaviour The gravitational force between two bodies outside a uniform field (for example, between the Earth and the Sun) is defined by Newton’s Law of Gravitation w...
Orbital Motion, Speed & Energy Since most planets and satellites have a near circular orbit, the gravitational force?FG?between the sun or another planet provides the?centripetal force?needed t...
Escape Speed To escape a gravitational field, a mass must travel at the?escape velocity This is dependent on the mass and radius of the object creating the gravitational field, such as a planet, a ...
Potential in a Charged Sphere The?electric potential?in the field due to a?point charge?is defined as:Where: V?= the electric potential (V) Q?= the point charge producing the potential (C) ε0?=?per...
更多國際賽事干貨/真題、藤校學(xué)霸故事，關(guān)注【翰林課程】公眾號(hào)！ 一波未平一波又起！ 今年3月，哥大教授發(fā)表長(zhǎng)文質(zhì)疑哥大在U.S.News排名中數(shù)據(jù)造假，“引爆”了留學(xué)圈。上月月初，哥大已經(jīng)官宣退出U.S.News 2023年...
