Govt. Exams
Entrance Exams
In a triode, the grid (control electrode) placed between cathode and anode controls electron flow through electrostatic fields, enabling amplification of signals applied to the grid.
Varactor (variable capacitor) diodes are reverse-biased devices whose junction capacitance varies with applied voltage. They are used in voltage-controlled oscillators, frequency modulators, and tuning circuits.
VCEO (max) is a critical parameter specifying the maximum collector-emitter voltage the transistor can withstand without avalanche breakdown. Exceeding this rating can permanently damage the device.
Pinch-off voltage (Vp) for a JFET is the reverse gate-source voltage magnitude at which the channel becomes completely depleted, causing drain current to drop to approximately zero.
Photodiodes operate in reverse bias and generate photocurrent proportional to incident light intensity. They are used in optical communication systems, light sensors, and imaging applications.
Threshold voltage (Vth) is the minimum gate-source voltage required to create an inversion layer and form a conducting channel between drain and source in a MOSFET.
Thermal resistance θJA (junction to ambient) determines how effectively heat is dissipated. Lower θJA values indicate better heat dissipation capability, essential for power dissipation calculations: Tj = Ta + (P × θJA).
