EXPERIMENT 6 FET CHARACTERISTIC CURVES ________________________________________ Bring a diskette to save your data. ________________________________________ OBJECT: The objective of this lab is to investigate the DC characteristics and operation of a field effect transistor (FET). The FET recommended to be used in this lab is 2N5486 n-channel FET. • Gathering data for the DC characteristics ________________________________________ APPARATUS: Dual DC Power Supply, Voltmeter, and 1k resistors, 2N5486 N-Channel FET. ________________________________________ THEORY: A JFET (Junction Field Effect Transistor) is a three terminal device (drain, source, and gate) similar to the BJT. The difference between them is that the JFET is a voltage controlled constant current device, whereas BJT is a current controlled current source device. Whereas for BJT the relationship between an output parameter, iC, and an input parameter, iB, is given by a constant , the relationship in JFET between an output parameter, iD, and an input parameter, vGS, is more complex. PROCEDURE: Measuring ID versus VDS (Output Characteristics) 1. Build the circuit shown below. 2. Obtain the output characteristics i.e. ID versus VDS. a. Set VGS = 0. Vary the voltage across drain (VDS) from 0 to 8 V with steps of 1 V and measure the corresponding drain current (ID). b. Repeat the procedure for different values of VGS. (0V, -0.5V, -1V, -1.5V, -2V, -2.5V, -3.0V, -3.5V, -4.0V). 3. Record the values in Table 1 and plot the graph ID vs. VGS. VGS 0 -0.5 -1.0 -1.5` -2.0 -2.5 -3.0 -3.5 -4.0 VDS ID ID ID ID ID ID ID ID ID 0 0 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0mA 1 0 0.7 mA 0.7 mA 0.66 mA 0.6 mA 0.6 mA 0.5 0.1mA 0mA 2 0 1.5 mA 1.3 mA 1.3mA 1.2 mA 1.1 mA 0.7 0.1mA 0mA 3 0 2.1 mA 2.6 mA 1.9 mA 1.8 mA 1.5 mA 0.8 mA 0.1mA 0mA 4 0 2.7 mA 2.6 mA 2.5 mA 2.4 mA 1.7 mA 0.8 mA 0.1mA 0mA 5 0 3.4 mA 3.3 mA 3.1 mA 2.8 mA 1.8 mA 0.9 mA 0.1mA 0mA 6 0 4.1 mA 3.4 mA 3.7 mA 3.2 mA 1.9 mA 0.9 mA 0.1mA 0mA 7 0 4.7 mA 4.5 mA 4.2 mA 3.4 mA 1.9 mA 0.9 mA 0.1mA 0mA 8 0 5.3 mA 5.1 mA 6.6 mA 3.5 mA 2.0 mA 0.9 mA 0.1mA 0mA Table 1. vds=0:8; id=[0 6.2e-3 9.7e-3 11.3e-3 11.9e-3 12.2e-3 12.3e-3 12.3e-3 12.32e-3]; plot(vds,id);grid on;hold on id2=[0 5.23e-3 8.05e-3 9.15e-3 9.57e-3 9.77e-3 9.88e-3 9.9e-3 9.92e-3]; plot(vds,id2);grid on;hold on id3=[0 4.29e-3 6.41e-3 7.17e-3 7.46e-3 7.60e-3 7.67e-3 7.73e-3 7.76e-3]; plot(vds,id3);grid on;hold on ________________________________________ Measuring ID versus VGS (Transconductance Characteristics) 1. For the same circuit, obtain the transconductance characteristics. i.e. ID versus VGS. a. Set a particular value of voltage for VDS, i.e. 5V. Start with a gate voltage VGS of 0 V, and measure the corresponding drain current (ID). b. Then decrease VGS in steps of 0.5 V until VGS is -4V. c. At each step record the drain current. VDS = 5 V VGS ID 0 3.42 mA -0.5 3.36 mA -1.00 3.27 mA -1.50 3.12 mA -2.00 2.79 mA -2.50 1.84 mA -3.00 0.71 mA -3.50 0.11 mA -4.00 0 mA Table 2. 2. Plot the graph with ID versus VGS using Excel, MATLAB, or some other program. Discussion Questions—Make sure you answer the following questions in your discussion. Use all of the data obtained to answer the following questions: 1. Discuss the output and transconductance curves obtained in lab? Are they what you expected? 2. Are the output characteristics spaced evenly? Should they be? 3. What are the applications of a JFET?

## EXPERIMENT 6 FET CHARACTERISTIC CURVES ________________________________________ Bring a diskette to save your data. ________________________________________ OBJECT: The objective of this lab is to investigate the DC characteristics and operation of a field effect transistor (FET). The FET recommended to be used in this lab is 2N5486 n-channel FET. • Gathering data for the DC characteristics ________________________________________ APPARATUS: Dual DC Power Supply, Voltmeter, and 1k resistors, 2N5486 N-Channel FET. ________________________________________ THEORY: A JFET (Junction Field Effect Transistor) is a three terminal device (drain, source, and gate) similar to the BJT. The difference between them is that the JFET is a voltage controlled constant current device, whereas BJT is a current controlled current source device. Whereas for BJT the relationship between an output parameter, iC, and an input parameter, iB, is given by a constant , the relationship in JFET between an output parameter, iD, and an input parameter, vGS, is more complex. PROCEDURE: Measuring ID versus VDS (Output Characteristics) 1. Build the circuit shown below. 2. Obtain the output characteristics i.e. ID versus VDS. a. Set VGS = 0. Vary the voltage across drain (VDS) from 0 to 8 V with steps of 1 V and measure the corresponding drain current (ID). b. Repeat the procedure for different values of VGS. (0V, -0.5V, -1V, -1.5V, -2V, -2.5V, -3.0V, -3.5V, -4.0V). 3. Record the values in Table 1 and plot the graph ID vs. VGS. VGS 0 -0.5 -1.0 -1.5` -2.0 -2.5 -3.0 -3.5 -4.0 VDS ID ID ID ID ID ID ID ID ID 0 0 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0.002mA 0mA 1 0 0.7 mA 0.7 mA 0.66 mA 0.6 mA 0.6 mA 0.5 0.1mA 0mA 2 0 1.5 mA 1.3 mA 1.3mA 1.2 mA 1.1 mA 0.7 0.1mA 0mA 3 0 2.1 mA 2.6 mA 1.9 mA 1.8 mA 1.5 mA 0.8 mA 0.1mA 0mA 4 0 2.7 mA 2.6 mA 2.5 mA 2.4 mA 1.7 mA 0.8 mA 0.1mA 0mA 5 0 3.4 mA 3.3 mA 3.1 mA 2.8 mA 1.8 mA 0.9 mA 0.1mA 0mA 6 0 4.1 mA 3.4 mA 3.7 mA 3.2 mA 1.9 mA 0.9 mA 0.1mA 0mA 7 0 4.7 mA 4.5 mA 4.2 mA 3.4 mA 1.9 mA 0.9 mA 0.1mA 0mA 8 0 5.3 mA 5.1 mA 6.6 mA 3.5 mA 2.0 mA 0.9 mA 0.1mA 0mA Table 1. vds=0:8; id=[0 6.2e-3 9.7e-3 11.3e-3 11.9e-3 12.2e-3 12.3e-3 12.3e-3 12.32e-3]; plot(vds,id);grid on;hold on id2=[0 5.23e-3 8.05e-3 9.15e-3 9.57e-3 9.77e-3 9.88e-3 9.9e-3 9.92e-3]; plot(vds,id2);grid on;hold on id3=[0 4.29e-3 6.41e-3 7.17e-3 7.46e-3 7.60e-3 7.67e-3 7.73e-3 7.76e-3]; plot(vds,id3);grid on;hold on ________________________________________ Measuring ID versus VGS (Transconductance Characteristics) 1. For the same circuit, obtain the transconductance characteristics. i.e. ID versus VGS. a. Set a particular value of voltage for VDS, i.e. 5V. Start with a gate voltage VGS of 0 V, and measure the corresponding drain current (ID). b. Then decrease VGS in steps of 0.5 V until VGS is -4V. c. At each step record the drain current. VDS = 5 V VGS ID 0 3.42 mA -0.5 3.36 mA -1.00 3.27 mA -1.50 3.12 mA -2.00 2.79 mA -2.50 1.84 mA -3.00 0.71 mA -3.50 0.11 mA -4.00 0 mA Table 2. 2. Plot the graph with ID versus VGS using Excel, MATLAB, or some other program. Discussion Questions—Make sure you answer the following questions in your discussion. Use all of the data obtained to answer the following questions: 1. Discuss the output and transconductance curves obtained in lab? Are they what you expected? 2. Are the output characteristics spaced evenly? Should they be? 3. What are the applications of a JFET?

No expert has answered this question yet. You can browse … Read More...
Task 4 – Learning Outcome 2.1 Apply dimensional analysis to energy and mass transfer relationships a. The Reynolds number (Re) is a function of density, viscosity, and velocity of a fluid and a characteristic length (diameter of the pipe). Establish that Re = C (Vdr/m )-d by dimensional analysis and suggest appropriate methods to obtain constants C and d.

## Task 4 – Learning Outcome 2.1 Apply dimensional analysis to energy and mass transfer relationships a. The Reynolds number (Re) is a function of density, viscosity, and velocity of a fluid and a characteristic length (diameter of the pipe). Establish that Re = C (Vdr/m )-d by dimensional analysis and suggest appropriate methods to obtain constants C and d.

Toyota Motor Corporation  Ever since 1957, after the Crown was … Read More...
9. Identify and discuss the trade-offs associated with operating a supply chain that handles both forward and reverse movements as compared with separate supply chains for these movements.

## 9. Identify and discuss the trade-offs associated with operating a supply chain that handles both forward and reverse movements as compared with separate supply chains for these movements.

By strategic plan, forward supply chains normally struggle to be … Read More...
Faculty of Science Technology and Engineering Department of Physics Senior Laboratory Faraday rotation AIM To show that optical activity is induced in a certain type of glass when it is in a magnetic field. To investigate the degree of rotation of linearly polarised light as a function of the applied magnetic field and hence determine a parameter which is characteristic of each material and known as Verdet’s constant. BACKGROUND INFORMATION A brief description of the properties and production of polarised light is given in the section labelled: Notes on polarisation. This should be read before proceeding with this experiment. Additional details may be found in the references listed at the end of this experiment. Whereas some materials, such as quartz, are naturally optically active, optical activity can be induced in others by the application of a magnetic field. For such materials, the angle through which the plane of polarisation of a linearly polarised beam is rotated () depends on the thickness of the sample (L), the strength of the magnetic field (B) and on the properties of the particular material. The latter is described by means of a parameter introduced by Verdet, which is wavelength dependent. Thus:  = V B L Lamp Polariser Solenoid Polariser Glass rod A Solenoid power supply Viewing mirror EXPERIMENTAL PROCEDURE The experimental arrangement is shown in the diagram. Unpolarised white light is produced by a hot filament and viewed using a mirror. • The light from the globe passes through two polarisers as well as the specially doped glass rod. Select one of the colour filters provided and place in the light path. Each of these filters transmits a relatively narrow band of wavelengths centred around a dominant wavelength as listed in the table. Filter No. Dominant Wavelength 98 4350 Å 50 4500 75 4900 58 5300 72 B 6060 92 6700 With the power supply for the coil switched off, (do not simply turn the potentiometer to zero: this still allows some current to flow) adjust one of the polarisers until minimum light is transmitted to the mirror. Minimum transmission can be determined visually. • Decide which polariser you will work with and do not alter the other one during the measurements. • The magnetic field is generated by a current in a solenoid (coil) placed around the glass rod. As the current in the coil is increased, the magnitude of the magnetic field will increase as shown on the calibration curve below. The degree of optical activity will also increase, resulting in some angle of rotation of the plane of polarisation. Hence you will need to rotate your chosen polariser to regain a minimum setting. 0 1 2 3 4 5 0.00 0.02 0.04 0.06 0.08 I (amps) B (tesla) Magnetic field (B) produced by current (I) in solenoid • Record the rotation angle () for coil currents of 0,1,2,3,4 and 5 amps. Avoid having the current in the coil switched on except when measurements are actually being taken as it can easily overheat. If the coil becomes too hot to touch, switch it off and wait for it to cool before proceeding. • Plot  as a function of B and, given that the length of the glass rod is 30 cm, determine Verdet’s constant for this material at the wavelength () in use. • Repeat the experiment for each of the wavelengths available using the filter set provided. • Calculate the logarithm for each V and  and tabulate the results. By plotting log V against log , determine the relationship between V and . [Hint: m log(x) = log (xm) and log(xy) = log(x) + log(y)]. • Calculate the errors involved in your determination of V. The uncertainty in a value of B may be taken as the uncertainty in reading the scale of the calibration curve) • The magnetic field direction can be reversed by reversing the direction of current flow in the coil. Describe the effect of this reversal and provide an explanation. Reference Optics Hecht.