Definition: A varistor is a 2 terminal semiconductor device that protects the electrical and electronic devices from overvoltage transients. Its resistance is dependent on the applied input voltage. The word varistor is formed by the combining variable and resistor. It is also known as voltage-dependent resistor, VDR whose resistance changes automatically with the corresponding change in …
Definition: A semiconductor device that generates coherent light of high intensity is known as laser diode. LASER is an abbreviation for Light Amplification by Stimulated Emission of Radiation. Stimulated emission is the basis of working of a laser diode. Laser diode is similar to LED, however, different from LED, the PN junction of laser diode …
Definition: A special type of PN junction device that generates current when exposed to light is known as Photodiode. It is also known as photodetector or photosensor. It operates in reverse biased mode and converts light energy into electrical energy. The figure below shows the symbolic representation of a photodiode: Principle of Photodiode It works …
Definition: The bridge which measures the unknown mutual inductance regarding mutual inductance such type of bridge is known as the Campbell bridge. The mutual inductance is the phenomenon in which the variation of current in one coil induces the current in the nearer coil. The bridge also used for measuring the frequency by adjusting the …
Definition: When the beam of the light enlightens the surface of the metals like sodium, potassium, caesium and rubidium then their electrons start emitting. The phenomenon of emission of electrons is known as the photoelectric emission. In other words, the photoelectric emission is the process through which the free electrons are liberated from the surface …
Definition: The potential barrier in the PN-junction diode is the barrier in which the charge requires additional force for crossing the region. In other words, the barrier in which the charge carrier stopped by the obstructive force is known as the potential barrier. How It gets established? When the P and N-type semiconductor material are placed …
Definition: The phototransistor is a three-layer semiconductor device which has a light-sensitive base region. The base senses the light and converts it into the current which flows between the collector and the emitter region. The construction of phototransistor is similar to the ordinary transistor, except the base terminal. In phototransistor, the base terminal is not …
Definition: The diode in which the intrinsic layer of high resistivity is sandwiched between the P and N-region of semiconductor material such type of diode is known as the PIN diode. The high resistive layer of the intrinsic region provides the large electric field between the P and N-region. The electric field induces because of …
Definition: The tunnel diode is a highly conductive, heavily doped PN-junction diode in which the current induces because of the tunnelling. The tunnelling is the phenomenon of conduction in the semiconductor material in which the charge carrier punches the barrier instead of climbing through it. The tunnel diode is a heavily doped PN-junction diode. The …
Definition: The diode whose internal capacitance varies with the variation of the reverse voltage such type of diode is known as the Varactor diode. It is used for storing the charge. The varactor diode always works in reverse bias, and it is a voltage-dependent semiconductor device The voltage-dependent device means the output of the diode depends …
