The differential amplifier (shown in fig below) is also referred to as along-tailed pair. A differential amplifier contains 2 inputs namely, vIN1 and vIN2. This amplifier is used as amplifier in order to amplify the voltage difference between its inputs. When it does this, we say that it is operating in the differential mode.
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Showing posts with label ac circuit tutorial. Show all posts
Showing posts with label ac circuit tutorial. Show all posts
FERROMAGNETISM
Ferro-magnetism is very commonly used type of magnetism. Ferromagnetism is found on the Bar magnets, compass needles, and the coating on magnetic hard disks. It is a fine property of iron, cobalt, and compounds of these few other metals which includes nickel, chromium and magnesium. All these stated materials shows ferromagnetic properties because the spins of the electrons cancel out much less than in other materials. Groups of spinning electrons align readily with an external magnetic field, thus forming magnetic domains. This alignment is permanent so that the material becomes magnetized, & remains so, even when we remove the external field.
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Temperature coefficient of resistance
It is normal when the temperature of a material increases, the resistance increases in the most of conductors, insulators decrease in resistance, whilst the resistance of some special alloys remains almost constant.
The temperature coefficient of resistance of a material is the increase in the resistance of a 1OHM resistor of that material when it is subjected to a rise of temperature of 1◦C. Greek alpha is the symbol which is used for the temperature coefficient of resistance is “α”.
Thus, if some copper wire of resistance 1OHM is heated through 1◦C and its resistance is then measured as 1.0043OHM then α=0.0043Ω/Ω◦C for copper. The units are normally expressed only as ‘per ◦C’, i.e. α=0.0043/◦Cfor copper. If the 1Ω resistor of copper is heated through 100◦C then the resistance was at 100◦C would be 1+100x0.0043=1.43Ω_.
