drain resistane is basically the resistance offered by the drain terminal of the fet device.its the ratio of change in drain to source voltage to the change in drain current at a constant gate to source voltage.
It can be answered in two ways : 1. ratio of output & input voltages [Vout / Vin] i.e Drain voltage(Vds)/Source voltage(Vs). 2. multiplication of trans-conductance & drain resistance .
FET AS A VOLTAGE -VARIABLE RESISTOR (VVR):FET is operated in the constant current portion of its output characteristics for the linear applications .In the region before pinch off , where Vds is small the drain to source resistance rd can be controlled by the bias voltage Vgs.The FET is useful as a voltage variable resistor (VVR) or Voltage Dependent resistor.In JFET the drain source conductance gd = Id/Vds for small values of Vds which may be expressed as gd = gdo [ 1-( VgsVp)1/2 ] where gdo is the value of drain conductance when the bias voltage Vgs is zero.The variation of the rd with vgs can be closely approximated by rd = ro / 1- KVgs ro - drain resistance at zero gate bias and K constant dependent upon FET type.Small signal FET drain resistance rd varies with applied gate voltage Vgs and FET act like a VARIABLE PASSIVE RESISTOR.Advantagesof JFETVery high input impedance order of 100 ohmOperation of JFET depends on the bulk material current carriers that do not cross junctionsNegative temperature coefficientsVery high power gainSmaller size longer life and high efficiencyAc drain resistance rd it is the ratio of change in drain - source voltage to the change in drain current at constant gate source voltageTransconductance it is the ratio of change in drain current to the change in gate source voltageat constant drain source voltageAmplification factor it is the ratio of change in drain source voltage to the change in gate source voltage at constant drain current.
let the mosfet be biased in saturation regior. thus drain current in independent of drain to sourse voltage, the VI chara. is a curve, when this is extended till X axis at pt. Vds=-Va this is similar to effect in transistor the o/p resistance is slope of V-I chara.. it should ideally be infinite, but has some finite value due to "CHANNEL LENGTH MODULATION"
Roughly speaking, resistance. Transconductance refers to the reciprocal of the amplifying device's internal resistance. The concept is particularly useful if the device is a voltage-controlled current source (tube or FET). In vacuum tube amplifiers, transconductance (Gm) is (u / Rp), where... u is the amplification factor. u= (Gm x Rp). Rp is the anode (drain) resistance. Rp is the internal resistance of the amplifying device. Gfs is synonymous with Gm. The reciprocal of Gm (or Gfs) is (Rp / u). Another term for this reciprocal is transresistance.
B - Dynamic resistance
JFET BFW20 shows negetive resistance when gate is grounded (VGS = 0) and vary Drain to source voltage and measure Drain current. As the voltage is increased, the drain current decreases. Prof.S.Lakshminarayana.
drain resistance (rd) amplification factor trans conductance
To effectively unclog a drain using a drain snake, first insert the snake into the drain until you feel resistance. Rotate the snake handle to break up the clog, then slowly pull the snake out to remove the blockage. Repeat as needed until the drain is clear.
To effectively snake a bathroom drain, you can use a plumbing tool called a drain snake. Insert the snake into the drain and turn the handle to navigate it through the pipes. Once you feel resistance, rotate the snake to break up the clog. Pull out the snake and run water to check if the drain is clear.
To snake a sink drain effectively, first remove the drain stopper or trap. Insert a plumbing snake into the drain and turn the handle clockwise to break up clogs. Push the snake further down the drain until you feel resistance, then turn the handle counterclockwise to pull out the clog. Repeat as needed until the drain runs smoothly.
To effectively unclog a toilet drain using a toilet drain auger, first insert the auger into the drain until you feel resistance. Then, rotate the handle clockwise to break up the clog. Continue to push and twist the auger until the clog is cleared. Finally, flush the toilet to ensure the drain is unclogged.
To use a drain auger effectively to unclog a stubborn drain, first insert the auger into the drain until you feel resistance. Turn the handle clockwise to extend the auger further into the drain. Once you feel the blockage, continue turning the handle to break it up. Pull out the auger and run water to check if the drain is clear. Repeat the process if needed.
To effectively use a bathtub drain snake to unclog your drain, first insert the snake into the drain until you feel resistance. Then, turn the snake handle clockwise to break up the clog. Continue pushing and turning the snake until the clog is cleared. Finally, run hot water down the drain to flush out any remaining debris.
To effectively use a drain snake cable to unclog a stubborn drain, first insert the cable into the drain until you feel resistance. Then, rotate the cable clockwise to break up the clog. Continue pushing and rotating the cable until the clog is cleared. Finally, flush the drain with hot water to ensure it is fully unclogged.
Stainless steel screws are typically recommended for securing a shower drain in place due to their resistance to rust and corrosion in wet environments.
To effectively use a hand drain snake to unclog a stubborn drain, first insert the snake into the drain until you feel resistance. Then, turn the handle clockwise to push the snake further into the clog. Once you feel the snake break through the clog, slowly pull it out while continuing to turn the handle. Repeat this process until the drain is clear.
To effectively use a tub drain snake to unclog your bathtub drain, follow these steps: Insert the snake into the drain until you feel resistance. Rotate the snake handle clockwise to break up the clog. Continue pushing and rotating the snake until the clog is cleared. Pull the snake out of the drain and run water to check if the clog is removed.