Constant voltage drop model

Chapter 4 Ex and problem solution. advertisement. Exercise 4–1 Ex: 4.1 Refer to Fig. 4.3 (a). For v I ≥ 0, the diode conducts and presents a zero voltage drop. Thus v O = v I . For v I < 0, the diode is cut off, zero current flows through R, and v O = 0. The result is the transfer characteristic in Fig. E4.1.

Electrical Engineering questions and answers. Figure 1: Precision Rectifier 1. Characterize the relationship of input vs. output for the circuit in Figure 1. That is, find an expression for vivo. You can use the constant voltage drop model for the diodes.Expert Answer. Problem 1*. For the adjacent circuit, the op-amp is ideal. The diode can be modeled with a constant voltage drop model having a 0.7 volt drop when it is on a) Find the value of Vs that puts the diode at the boundary between on and off b) Make a plot of Vo versus V Note: Justify all assumptions briefly but clearly. R3 2K Problem 2*.In reality, voltage drop on diodes have an exponential relationship. Also, there are several different models for analyzing circuits that contain diodes. Taken from a textbook I use at school, Microelectronic Circuits 6th Ed, by Sedra and Smith: Graphical Analysis of the Exponential Model, using a load line. Constant Voltage Drop Model Consider a half-wave rectifier circuit with a triangular wave input of 5-V peak to peak amplitude and zero average, and with R=1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with V d =0.7V. Find the average value of v o. There are 4 steps to solve this one.Determine Vo and I in the diode circuit below using the constant-voltage-drop model. 1 k2 Vo 2 k2 5-10V. Electricity for Refrigeration, Heating, and Air Conditioning (MindTap Course List) 10th Edition. ISBN: 9781337399128.For the Circuit shown in Figure 1, find the operation point of the diode by (a) Ideal diode model (b) Constant voltage drop model with Von = 0.7V. Vdd 20 R; Vo R2 10 וס Figure 1 V dd = 5V, Ri=5k ohms R=lk ohms, R3= 2.2k ohms, and R=2.2k ohms.Engineering. Electrical Engineering. Electrical Engineering questions and answers. If R=10kΩ, find the value of the labeled current (ID2) in the following circuit, using the following 2 models: (Don't forget to ALWAYS confirm your assumptions!) a) Using the ideal model b) Using the constant voltage drop model assuming VD_ON=0.7 V.Expert Answer. 4.67 Consider the half-wave rectifier circuit of Fig. 4.23 (a) with the diode reversed. Let vs be a sinusoid with 10-V peak amplitude, and let R-1 kS2. Use the constant-voltage-drop diode model with Vp-0.7 V. (a) Sketch the transfer characteristic (b) Sketch the waveform of vo (c) Find the average value of vo (d) Find the peak ...

Assume that conducting diodes can be represented by the constant-voltage-drop model (VD = 0.7 ; This question hasn't been solved yet Ask an expert Ask an expert Ask an expert done loading. Question: 444 For the circuits in Fig. P4.10, utilize Thévenin's theo rem to simplify the circuits and find the values of the labeled currents and voltages.For the circuits in Fig. P4.10, utilize Thévenin's theorem to simplify the circuits and find the values of the labeled currents and voltages. Assume that conducting diodes can be represented by the constant-voltage-drop model $\left(V_{D}=0.7 \mathrm{V}\right)$.The voltage at a certain point is the work done to bring charges and placed them at this point per unit of charge. Voltage drop is the difference in voltages of two points. For example, if point A ...When a reverse bias voltage is applied the current through the diode is zero. When the current becomes greater than zero the voltage drop across the diode is zero. The non-linear character of the device is apparent from the examination of Figure 2. This simplified model gives a global picture of the diode behavior but it does not representElectrical Engineering questions and answers. Draw the output waveforms on the same graph with the given input, if V1 = 2 V and V2 =3 V. Use constant-voltage-drop model and assume both diodes have the knee voltage of 0.7. R1 2.2k0 6 V VI V2 M Vowe -6 V.4.67 Consider a half-wave rectifier circuit with a triangular-wave input of 6-V peak-to-peak amplitude and zero average, and with R=1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with VD =0.7 V. Find the average value of vO. Going off of what echad said, the constant voltage drop model is the simplest one, and speeds up analysis. In reality, voltage drop on diodes have an exponential relationship. Also, there are several different …

This video introduces the constant voltage drop (CVD) model for diodes as a means to abstract the non-linear behavior of the device. It also shows examples of how to use the CVD model to...Characterize the relationship of input vs. output for the circuit in Figure 1. That is, find an expression for vivo. You can use the constant voltage drop model for the diodes. 2. Assemble the circuit in LTSpice. For the op-amp, use the LM324, and use 1 N4148 diodes. The power rails should be set to 9 V and −9 V. 3. Apply aQuestion: Use the following diode circuit to answer the questions that follow: Use the constant voltage drop model with VD=0.7 to find I Use the constant voltage drop model with VD=0.7 to find Vx What are the states of the two diodes? Show transcribed image text. There are 3 steps to solve this one. Question: In the below circuit, we want to find: (a) The minimum voltage that Vin has to have to turn on the diode D1 and = (b) The maximum value that Vin can have without turn on the diode D2. Assume that the input is given by Vin = 6 cos[27 1000t], the diodes follow constant voltage drop model with VD, on = 650 mV and VB = 2V, R1 = 2 KN and R2 = …Use whatever exponential model you like to calculate the actual forward voltage of the diode at that specific current level. Change your ideal voltage source voltage to the calculated diode voltage. Repeat until the values of diode voltage and current converge to your satisfaction. Or, run a SPICE simulation.

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Expert Answer. Transcribed image text: 4.44 For the circuits in Fig. P4.8, utilize Thévenin's theorem to simplify the circuits and find the values of the labeled currents and voltages. Assume that conducting diodes can be represented by the constant-voltage-drop model (V D = 0.7 V) (a) (b)Electrical Engineering questions and answers. Figure 1: Precision Rectifier 1. Characterize the relationship of input vs. output for the circuit in Figure 1. That is, find an expression for vivo. You can use the constant voltage drop model for the diodes.Q5. Find the voltage V A in the circuit shown in Fig. 5 (i). Use simplified model. Fig. 5. Solution : It appears that when the applied voltage is switched on, both the diodes will turn “on”. But that is not so. When voltage is applied, germanium diode (V0 = 0.3 V) will turn on first and a level of 0.3V is maintained across the parallel circuit.Electrical Engineering. Electrical Engineering questions and answers. 4.67 Consider a half-wave rectifier circuit with a triangular-wave input of 6-V peak-to-peak amplitude and zero average, and with R = 1 k12. Assume that the diode can be represented by the constant-voltage-drop model with VD=0.7 V. Find the average value of vo.

Circuit analysis with 2 diodes : Constant Voltage model. It's a problem about sketching V_in V_out characteristics (sketching graph with V_in as x axis, V_out as y axis) with constant voltage model in different V_D,on (V_D1,on != V_D2, on) Starting from V_in = -inf, both D1 and D2 are turned off : (D1, D2) = (off, off) and it's obvious that V ...This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Question: 3. For the circuits shown below, find the values of the labeled voltages and currents using constant-voltage-drop model.4.38 Consider the circuit in Fig. 4.10 with Vpp = 3 V and R=3k12. (a) Find the current using a constant-voltage-drop model. (b) What value of l, is required to make this solution exact? (c) Approximately how much will the current change …Question: 4.40 Repeat Example 4.2 using the constant-voltage-drop (VD = 0.7 V) diode model. 4.40 Repeat Example 4.2 using the constant-voltage-drop (V D = 0.7 V) diode model. Show transcribed image text. There are 2 steps to …A1. 3 identical diodes in the circuit given in Fig A1. Use constant voltage drop model for the diodes with Vd=0.75V. Draw equivalent circuits and answer the following questions. (a) VI=5V, find I1, I2, and V0. (b) VI=-10V, find I1, I2, and V0. A2. Repeat A1(a) using a piece-wise diode model with VDo with 0.5V and rD = 25 ohms.Electrical Engineering questions and answers. Question 4. CVD Model Analysis [20pts] In the circuit below, assume the constant voltage drop model for the diodes and assume the turn-on voltage is 0.7 V. Calculate the values for current IR2 and ID2.Expert Answer. 4) For the circuits below, calculate the current flowing in the circuit using: (a) A constant voltage drop (CVD) model with a turn on voltage of 0.7 V. (b) An ideal diode equation with Is = 1 nA and n = 1 for all diodes. = 10 kilo-Ohms 10 kilo-Ohms 5V 5V +.Question: 4.67 Consider a half-wave rectifier circuit with a triangular-wave input of 6-V peak-to-peak amplitude and zero average, and with R = 1 k12. Assume that the diode can be represented by the constant-voltage-drop model with VD=0.7 V. Find the average value of vo. = Hint: This is a triangular waveform VI(t) Vp t MA A T/4 TX2 3T/4 AVPAnswer: B. Clarification: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since D1 is in forward biased there will be a voltage drop of 0.5V. So net voltage will be 2.5V and hence current is 2.5mA. 4.The constant forward voltage drop significantly helps with supply regulation; a normal diode typically drops an additional. 60mV for every 10 times change in ...This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Question: 3. For the circuits shown below, find the values of the labeled voltages and currents using constant-voltage-drop model.

Diodes | Constant Voltage Drop. StudyCat. 15 subscribers. Subscribe. 0. No views 8 minutes ago #diode #circuits. #diode #circuits In this video, we analyze diode …

constant-voltage-drop (VD = 0.7 V) diode model, find values of the labeled currents and voltages. ... Assume that when conducting the diode exhibits a constant voltage drop of 0.7 V. Find w _ , 00, and for: Also, find the average output voltage obtained when is a symmetrical square wave of 1 -kHz frequency, 5-V amplitude,1. The Constant Voltage Drop (CVD) Zener Model 2. The Piece-Wise Linear (PWL) Zener Model The Zener CVD Model Let’s see, we know that a Zener Diode in reverse bias can be described as: iI v V Zs Z ZK≈≈ <0 and Whereas a Zener in breakdown is approximately stated as: ivV ZZZK>≈0 and Q: Can we construct a model which behaves in a similar4.44 For the circuits in Fig. P4.8, utilize Thévenin's theorem to simplify the circuits and find the values of the labeled currents and voltages. Assume that conducting diodes can be represented by the constant-voltage-drop model (V D = 0.7 V) (a) (b)Tasers are capable of an output of 50,000 volts, but the voltage delivered to the body is only 1,200. The initial high voltage is used to establish a current between the two taser barbs. Immediately after contact with a body occurs, the vol...Solution for Using constant-voltage-drop model for diodes with Vy=0.7 V, find the values of the labeled voltages and currents shown in the circuit below.Expert Answer. Consider the half-wave rectifier circuit below. Let v_s be a sinusoid with 10-V peak amplitude, and let R = 1 kOhm. Use the constant-voltage-drop model with V_D = 0.7 V (a) Sketch the transfer characteristics (b) Sketch the waveform of v_0 (c) Find the average value of v_0 (d) Find the peak current of the diode (e) Find the PIV ...A voltage regulator is an electromechanical component used to maintain a steady output of volts in a circuit. It does this by generating a precise output voltage of a preset magnitude that stays constant despite changes to its load conditio...

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- Constant voltage drop model for diode. (a). Actual diode. (b). Ideal diode plus voltage source Von. (c). Composite i-v characteristic. +. -. 10 V. 10 k Ω. I.When a preset model is used, a generic value is loaded that corresponds to 1% of the nominal power (nominal voltage multiplied by the battery rated capacity). The resistance is constant during the charge and the …Q4: For the shown two circuits: a) Find the values of the labeled voltages and currents, assuming that the diodes are ideal. b) Find the values of the labeled voltages and currents, using the constant-voltage- drop (VD 0.7 V) diode model. +3V 3 V 12 kn 6 kO o V O V 6 k0 12 kn - 3 V - 3 V (b) (a) wUse (a)iteration and (b) the constant-voltage-drop model with Vd=0.7V. For the circuit in fig. 4.10, find Id and Vd for the case Vdd=5V and R=10K-ohms . Assume that the diode has voltage of 0.7V at 1-mA current. Use (a)iteration and (b) the constant-voltage-drop model with Vd=0.7V. Electrical Engineering questions and answers. Assume the diode in the circuit below is real and model it using the constant voltage drop model. Further assume V1=25 V, R1=368 12, R2=91212, R3=916 12, R4=1,060 12, and 11=0.009 A. Determine the voltage on the node labeled Vx. Express your answer in Volts and round to the 1st digit to the right of ...Expert Answer. For each of the circuits given below, assume that the diodes are following a constant voltage drop model with V on = 0.75 V. Match each circuit to the correct values of currents I D1 (Current on diode 1) and I D2 (current on diode 2) (a) (b) (c) (d) In the following circuit assume VX = 6.6 V, VY = 1.5 V,R1 = 3.6kΩ,R2 = 10kΩ ...constant-voltage-drop (VD = 0.7 V) diode model, find values of the labeled currents and voltages. ... Assume that when conducting the diode exhibits a constant voltage drop of 0.7 V. Find w _ , 00, and for: Also, find the average output voltage obtained when is a symmetrical square wave of 1 -kHz frequency, 5-V amplitude,The bridge rectifier circuit below has an input voltage, v; = 10sin(ot), where o= 103 radian/second. Use the diode constant voltage drop model assuming a turn on voltage of 0.7 V. You are given that R = 1k12. + D4 SLO VO + R DS AD? a. What is the peak current through the resistor? b. What is the peak inverse voltage (PIV) applied across any one ...3 Mar 2020 ... Constant Voltage Drop Model. So let's do another circuit. So this time, we're going to start with +6 volts. So have our node right there ... ….

Expert Answer. In any diode generally we have to find that when diode …. 1. Calculate the average value of the output waveform vo using integration techniques. Let vs = 5cos (21 (1000)t). Use the constant voltage drop model for the diode with Vp=0.7 V. Hih 1 V RL + } …1. The Constant Voltage Drop (CVD) Zener Model 2. The Piece-Wise Linear (PWL) Zener Model The Zener CVD Model Let’s see, we know that a Zener Diode in reverse bias can be described as: iI v V Zs Z ZK≈≈ <0 and Whereas a Zener in breakdown is approximately stated as: ivV ZZZK>≈0 and Q: Can we construct a model which behaves in a similar When a reverse bias voltage is applied the current through the diode is zero. When the current becomes greater than zero the voltage drop across the diode is zero. The non-linear character of the device is apparent from the examination of Figure 2. This simplified model gives a global picture of the diode behavior but it does not representExpert Answer. Transcribed image text: For the circuit below, the diodes are pn junction diodes with turn-on voltage at 0.7 V, using constant-voltage-drop model, to find VA,VB,ID1,IR1,IR2, IR3.Constant Voltage Drop Model. It is considered that the forward voltage drop of the diode is constant, the reverse resistance is infinite, and the reverse current is 0.Elliot Alderson. 31.2k 5 29 67. Ideal diode means zero voltage drop across diode in FB ,if you are talking about 0.7V drop across diode that is in the case of constant voltage drop model of a diode, So, if D1 is RB voltage drop across it will be 10V and across D2 zero. – user204283. Jul 12, 2020 at 18:54.Constant Voltage Drop Model. Now this is for plain silicon diodes, but the same math holds true for all diodes, just the parameters are slightly different and the drop for LEDs comes out different based on how they are manufactured. Share. Cite. Follow edited Jul 30, 2013 at 13:08. answered Jul ...Electrical Engineering. Electrical Engineering questions and answers. 1. Consider a half-wave rectifier circuit with a triangular-wave input of 5V peak-to-peak amplitude and zero average, and with R=1k2. Assume that the diode can be represented by the constant voltage drop model with V=0.7V. Find the average value of yo 2. Constant voltage drop model, So again, the only difference between the constant voltage drop and the ideal model is the fact that you put in a voltage source to say, okay, we're losing 0.7, or whatever your assumption is, 0.7 volts across this diode. And in most cases, it won't make a difference, but on occasion it will, it definitely will make things more complicated for you., A1. 3 identical diodes in the circuit given in Fig A1. Use constant voltage drop model for the diodes with Vd=0.75V. Draw equivalent circuits and answer the following questions. (a) VI=5V, find I1, I2, and V0. (b) VI=-10V, find I1, I2, and V0. A2. Repeat A1(a) using a piece-wise diode model with VDo with 0.5V and rD = 25 ohms., Consider a half-wave rectifier circuit with a triangular-wave input of 5-V peak-to-peak amplitude and zero average, and with R=1 \mathrm {k} \Omega. R= 1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with V_ {D}=0.7 \mathrm {V}. V D = 0.7V. Find the average value of v_ {O}. vO. Two diodes with saturation ..., For the circuits in Fig. P4.9, using the constant-voltage-drop (VD = 0.7 V) diode model, find the values of the labeled currents and voltages. This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. , For the circuits shown below, find the values of the labeled voltages and currents using constant-voltage-drop model. This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. See Answer See Answer See Answer done loading., Electrical Engineering questions and answers. Consider a half-wave rectifier circuit with a triangular-wave input of 5V peak-to-peak amplitude and zero average, and with R = 1k ohm. Assume that the diode can be represented by the constant voltage drop model with V_D = 0.7V. Find the average value of V_0., Expert Answer. Problem 3. Assume that vt = 10sinwt,V D = 0.7 V,V z = 6.8 V,R = 1kΩ. rz is negligibly small. Use the constant voltage drop model. Find v0 and plot the transfer characteristics. (2 pts) Problem 4. The 7.8 V Zener diode in the circuit is specified to have V Z = 7.8V at I Z = 5 mA,rz = 20Ω, and I ZK = 0.1 mA., Constant-voltage-drop model This is the most common diode model and is the only one we'll use in this class. It gives quite accurate results in most cases. i d forward bias vd reverse bias 0.7V 1 Assume the diode is operating in one of the linear regions (make an educated guess). 2 Analyze circuit with a linear model od the diode., Electrical Engineering. Electrical Engineering questions and answers. Question 2. Constant Voltage Drop Model In the circuit below, assume the constant voltage drop model for the diodes and assume the turn-on voltage is 0.7V. Calculate the values for current IÃ₂ and ID₂. [25 points] R1 R3 D1 1 ΚΩ 1.5 ΚΩ ID2 Vs 5V |+ 本 R2 2.2 ΚΩ IR2 D2., They are implemented as a voltage follower with series negative feedback driven by a constant input voltage source (i.e., a negative feedback voltage stabilizer).The voltage follower is loaded by a constant (current sensing) resistor acting as a simple current-to-voltage converter connected in the feedback loop. The external load of this current …, Electrical Engineering. Electrical Engineering questions and answers. 4.67 Consider a half-wave rectifier circuit with a triangular-wave input of 6-V peak-to-peak amplitude and zero average, and with R = 1 k12. Assume that the diode can be represented by the constant-voltage-drop model with VD=0.7 V. Find the average value of vo., At a constant 1A, the forward drop is about 1V. That's 1W, which is quite a bit for such a small device. With a 2% duty cycle, it's about .9V, or 20mW. I ..., May 1, 2023 · Find the Q-points for the diodes in the four circuits in Fig. P3.68 using (a) the ideal diode model and (b) the constant voltage drop model with Von = 0.7 V. Note that Resistor = 15kOhm. The second picture is my solution, I don't know if it is right or wrong. , Engineering. Electrical Engineering. Electrical Engineering questions and answers. Consider a half-wave rectifier circuit with a triangular wave input of 5-V peak to peak amplitude and zero average, and with R=1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with Vd=0.7V. Find the average value of vo., 1. The Constant Voltage Drop (CVD) Zener Model 2. The Piece-Wise Linear (PWL) Zener Model The Zener CVD Model Let’s see, we know that a Zener Diode in reverse bias can be described as: iI v V Zs Z ZK≈≈ <0 and Whereas a Zener in breakdown is approximately stated as: ivV ZZZK>≈0 and Q: Can we construct a model which behaves in a similar, 4.3 Diode Circuit Models Diodes present a circuit analysis challenge compared to linear devices (such as resistors) owing to the complex shape of the diode curve. Unlike a resistor, there isn’t an exact analytical expression relating voltage and current in a diode that can be written down and used in KVL and KCL and node voltage analyses described in chapter 3., 1 Answer Sorted by: 0 My question is ,Why Diode On voltage is the only cause for the current flow through R_1 ? If you are modeling the forward conduction of the diode as a constant voltage then there is also a constant voltage across R1. With a constant voltage across R1, due to ohm's law the current through R1 is constant., Final answer. 3. For the circuits shown below, find the values of the labeled voltages and currents using constant-voltage-drop model. 4. The input signal vin for the following circuit is given. Draw the waveform of vout on the same graph with vin. Use the constant-voltage-drop model and assume the knee voltage of the diode is 0.7 V., Electrical Engineering questions and answers. Figure 1: Precision Rectifier 1. Characterize the relationship of input vs. output for the circuit in Figure 1. That is, find an expression for vivo. You can use the constant voltage drop model for the diodes., For the circuits shown below, find the values of the labeled voltages and currents using constant-voltage-drop model. This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. , Question: For each of the circuits given below, assume that the diodes are following a constant voltage drop model with Von=0.75 V. Match each circuit to the correct values of currents ID1 (Current on diode 1) and ID2 (current on diode 2) (a) (b) (c) (d)Circuit (a) Circuit (b) Circuit (c) Circuit (d), 7 Mar 2011 ... Solved: Multisim11 student evaluation version. In a simple dc series circuit with a 10ohm resistor and (3) in4148 diodes forward biased, ..., Consider a half-wave rectifier circuit with a triangular wave input of 5-V peak to peak amplitude and zero average, and with R=1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with V d =0.7V. Find the average value of v o. There are 4 steps to solve this one. , 4.67 Consider a half-wave rectifier circuit with a triangular-wave input of 6-V peak-to-peak amplitude and zero average, and with R=1kΩ. Assume that the diode can be represented by the constant-voltage-drop model with VD =0.7 V. Find the average value of vO. , Final answer. 1. Find the current I, the voltage V, and the Q-point for the diode In the four diode circuits below (i through iv): (a) using the ideal diode model; (b) Repeat (a) using the constant voltage drop model for the diode with VoN = 0.7 V., Explanation: Since at constant voltage drop model voltage drop across diode at forward bias is a constant. In this circuit if input is negative diode is reverse bias hence no current. So for negative input output is zero. For positive input V out will be equal to input with a voltage drop of V D., 2/6/2012 The Constant Voltage Drop Model present 1/16 Jim Stiles The Univ. of Kansas Dept. of EECS The Constant Voltage Drop (CVD) Model Q: We know if significant positive current flows through a junction diode, the diode voltage will be some value near 0.7 V. Yet, the ideal diode model provides an approximate answer of vD =0 V. , Electrical Engineering. Electrical Engineering questions and answers. Consider the circuit shown in the figure below. Assume that the diodes can be modeled by the constant-voltage- drop diode model, having a voltage drop VD 07 V when conducting (see Fig. 6 in Question 5). The input voltage vr is a sine wave with a 10-V peak amplitude., If a constant 0.7v is too wrong for your purposes, let's say you want to estimate the diode voltage drop at 1nA, then you would use a better …, For a silicon diode to turn on, it needs 0.7V. A voltage of 0.7V or greater is fed to turn on the forward-biased diode. The diode turns off if the voltage is less than 0.7V. second-approximation Third Diode Approximation. The third approximation of a diode includes voltage across the diode and voltage across bulk resistance, R B., Jun 27, 2016 · In Figure 1.2 (A), the half-wave rectifier is illustrated. In this article, we will use the constant voltage drop (CVD) model of a diode owing to its simplicity. From this model, we are provided with. v0 = 0 v 0 = 0 when vS < V D v S < V D. Equation 1.1 (A) v0 = vS− V D v 0 = v S − V D when vS ≥ V D v S ≥ V D. , The diode is non ohmic and non linear semiconductor device. The thermal voltage, or Vt of the junction, is referred to as the term kT/q describes the voltage produced within the P-N junction as a result of the action of temperature. This amounts to around 26 millivolts at ambient temperature. A "nonideality" coefficient of 1 are assumed., Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since D1 is in forward biased there will be a voltage drop of 0.5V. So net voltage will be 2.5V and hence current is 2.5mA.