ampere is the s.i unit of electric current.
what is the s.i unit of electric current?
ampere
the si unit of electric current is the ampere, which is the flow of electric charge across a surface at the rate of one coulomb per second. the ampere (symbol: a) is an si base unit electric current is measured using a device called an ammeter.





























electric currents cause joule heating, which creates light in incandescent light bulbs. they also create magnetic fields, which are used in motors, inductors and generators.
electric current
evidence of lightning activity can often be found in the paleomagnetic record. lightning strikes are the result of tremendous charge buildup in clouds. this excess charge is transferred to the ground via lightning channels, which carry a strong electric current. because of the intensity of this electric current, when lightning hits the ground, it can produce a strong, albeit brief, magnetic field. thus, as the electric current travels through soils, rocks, plant roots, etc., it locks a unique magnetic signature within these materials through a process known as lightning-induced remanent magnetization (lirm). evidence of lirm is manifested in concentric magnetic field lines surrounding the location of the lightning strike point. lirm anomalies normally occur close to the location of the lightning strike, usually encapsulated within several meters of the point of contact. the anomalies are generally linear or radial, which, just like actual lightning channels, branch out from a central point. it is possible to determine the intensity of the electric current from a lightning strike by examining the lirm signatures. since rocks and soils already have some preexisting magnetic field, the intensity of the electric current can be determined by examining the change between the "natural" magnetic field and the magnetic field induced by the lightning current, which generally acts parallel to the direction of the lightning channel. another characteristic feature of an lirm anomaly compared to other magnetic anomalies is that the electric current intensity is generally stronger. however, some have suggested that the anomalies, like other characteristics in the geologic record, might fade over time as the magnetic field redistributes.
paleolightning