At the heart of the debate is a simple and well-understood physical phenomenon: When an electric current passes through a wire, it generates an electromagnetic field that exerts forces on surrounding objects. For many years, scientists dismissed any suggestion that such forces might be harmful, ...
How does an electric field produce a magnetic field? What generates the magnetic field in a current carrying wire? How is the magnetic field oriented around a magnet? How to find electric field from magnetic field? What is the SI unit for the strength of a magnetic field?
Both RFID and NFC operate on the principle of inductive coupling, at least for short-range implementations. This essentially involves a reader device passing an electric current through a coil, which in turn generates a magnetic field. When you bring a tag (with its own coil) near the reader...
Which energy source generates the least greenhouse gases? What is the ultimate source of electromagnetic waves? Why is the sun a source of non-ionizing radiation? Where does the energy in fission come from? Where does dark energy come from?
A flowing current generates a magnetic field in the shape of concentric circles. The strength of the field is proportional to the magnitude of the current, and the direction of the field is equivalent to the direction a screw is turned to tighten it. This principle, which is utilized by cla...
Magnet– generates a magnetic field that can affect the overall sound quality of the headphones Voice coils– move the diaphragm to create the sound you hear when an electric current passes through them Diaphragm– vibrates to create sound waves that human ears can pick up ...
resonance, and the first step is to build a coil of electrical wire thatgenerates a magnetic field when power is attached. When another coil is brought nearby, an electrical charge is generated. And this power can then be transferred to whatever device you like – a lightbulb for example....
A charge moving in a straight line, as through a straight wire, generates a magnetic field that spirals around the wire. When that wire is formed into a loop, the field becomes a doughnut shape, or a torus. Direct current can also produce a constant field in one direction that can be...
While electricity follows a certain path from a point of origin to a receiving point and back, magnetism always flows from one pole to the other. As magnetism flows through the circuit, it produces lines of force, or flux lines, and generates a magnetic field. In simplest terms, anything ...
A magnetic resonance imaging apparatus (A) generates a uniform magnetic field, causes gradient fields transversely thereacross, excites resonance in nuclei within the image region, receives radio frequency signals from resonating nuclei,... DM Blakeley,RE Gangarosa - US 被引量: 110发表: 1991年 Act...