Ccg constant current generator, j x current density e electron, b applied magnetic field t thickness, w width v h hall voltage. Highway engineering lab viva questions with answers. The hall effect is the production of a voltage difference the hall voltage across an electrical conductor, transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current. The planar hall effect is inherently connected to an anisotropic magnetoresistance amr essentially different longitudinal resistivities for magnetic field aligned or. Viva voce question and answer based on screw gauge experiment in hindisciencephysics this video will. The idea of hall effect electron velocity vd is taken to vary linearly with the field ex. When a current carrying conductor is placed in a magnetic field mutually perpendicular to the direction of current a potential difference is developed at right angle to both the magnetic and electric field. This is most evident in a thin flat conductor as illustrated. Gaas hall element has high sensitivity, wide linear range, and small temperature coefficient. How is hall s coe fficient related to the hall s voltage vh and the thicknesst. Where to download engineering physics lab viva dear subscriber, in imitation of you are hunting the engineering physics lab viva buildup to gain access to this day, this can be. Finally, in october, 1879, hall measured the lateral potential difference successfully.
If an electron of sufficient voltage is passed across a material then a. Gokarajurangaraju institute of engineering and technology autonomous bachupally, kukatpally, hyderabad 500 090, a. The production of transverse voltage across a current carrying conductor when placed in a perpendicular magnetic field,is called hall effect. The modification in the distribution of intensity in the region of superposition. Assume the conductor to have charge carrier of charge q can be either positive or negative or.
Notice that the neon in the tube is fluorescing emitting light due to the excitation of the electrical current supplied from the battery. The hall effect was discovered in 1879 by edwin herbert hall while working on his doctoral degree at the johns hopkins university in baltimore, maryland, usa discovered 18 years before the electron. In the experiment setup window, click analog port a and select \magnetic field sensor, and then click \ok. The voltage at which the zener diode breaks down is called the zener voltage. Using a hall effect sensor to make a tachometer duration. In the hall effect experiment, we determine the hall voltage and hall coefficient.
On each sample, measure resistivity and hall voltages by following the instructions in the nist manual and filling out the handy worksheet from the nist manual. Hall effect wikipedia experiment by students of iit patna. Hall coefficient increases with decrease in number of charge carriers per unit volume. Experimently find out whether the given diode is made of germanium or silicon. In measuring v h, the following is the accurate method.
When light falls on metal surface, an electron is emitted from a metal if the energy of the photon is greater than the work function of the metal. To study the hall effect and determine hall coeffcient, carrier density and mobility of a given semiconductor using hall effect set up. Harsh shukla hall sensor hall effect and its applications hall effect thruster 2. Scientific principles applications previous setup shortcomings new setup how it works possible improvements results conclusion hall effect. The hall effect and its applications 103 by assuming a twoband model with one electron and one hole band, the conductivity of each being independent of the magnetic field, one finds a change of resistivity caused by a transversal magnetic field given by the following expression 5.
I recently performed this experiment in the solid states lab during the ii semester for m. Please read the radiation safety regulations at the back of this book objectives of the experiment the behaviour of the hall voltage in a sample of doped germanium is studied in three different setups as follows. Laboratory manual physics 1 agh university of science. Zener diode is a pn junction diode specially designed for operation in the breakdown region in reverse bias condition. To find the specific rotation of sugar solution by using a polarimeter. The crystal is covered by a protective layer of paint. Conduct the experiment for obtaining the forward bias vi characteristics of the given diode. When a charged particle is placed or moving in the presence of the electric and magnetic field, the total forces due to these fields on the charged particle known as lorentz force. This slider activate only if hall effect setup is selected. Carrier concentration is the number or carriers per unit volume. A pure semiconductor completely free from impurities is called intrinsic semiconductor. The redistribution of light by superposition of light waves is called as interference. To determine the energy band gap of a given semiconductor material. The allocation of marks for physics practical sessional is shown below.
The fundamental quantum of hall resistance is he2 25,8. Why is the hall coeffi cient of semiconductors many orders of magnitude sgreater than that of metals. Excellent questions we can score full marks in viva through this questions. When the two or more waves superimpose over each other, resultant intensity is modified. Viva questions related to the hall effect experiment are mentioned here. Most likely you have knowledge that, people have see numerous period for their favorite books considering this hall effect experiment viva questions, but stop taking place in harmful downloads. Classical hall effect in scanning gate experiments. This part describes the hall effect apparatus, as well as the procedures for computer control and data collection. A buildup of charge at the sides of the conductors will balance this magnetic influence, producing a measurable. The hall coefficient enables also establishing the concentration of the carriers in the sample n. This apparatus is purposed to help students understand the principle of hall effect, measure the sensitivity of a hall element, and learn how to use a hall element to measure magnetic field intensity. Investigating the hall effect in silver objects of the experiment g validation of the proportionality of the hall voltage and the magnetic flux density. The whole system is mounted in a pen type case for further protection.
The hall effect experiment is explained very briefly i just tried to make it brief. Pdf as a song to pull off it is not provided in this website. We were supposed to observe the hall effect in semiconductors and measure the hall coefficient rh and. Gradient vs super elevation 7 viva questions answers civil engineering. This is known as the hall effect, named after american physicist edwin hall, who discovered the phenomenon in 1879. Is it possible to measure hall s coe fficient for metals. Experiment 20 the hall effect university college dublin. This effect is particularly pronounced in thin metals, and is easily observable in a lowdensity plasma an electrically conductive ionized gas, such as a fluorescent light, as in this tutorial. The hall effect is the production of a voltage difference the hall voltage across an electrical. In this phenomenon, electromagnetic radiation is absorbed as it flips spins from low energy to high energy states. It is used to verify if a substance is a semiconductor,conductor or insulator.
However, when measuring very small magnetic fields 100x 10 gauss, some temperature dependent variation may be observed in the sensor output. At this time, hall used thin gold foil to accomplish the experiment. Thin film samples consisting of a semiconductor inas and two different metals aluminum and gold are investigated to determine the sign and density of the. Viva voce question answer with explanation for ohms. The ends of the hall effect tube a vacuum with a trace of neon gas are connected to a battery. Last day of the experiment please ll out the experiment evaluation suggested reading. First some current 1a is sent through the electromagnet to.
Alpha watercooled magnet and power supply turn on water before turning on power supply. And this is used to select the material for finding hall coefficient and carrier concentration. This is used to select the part of the experiment to perform 1 magnetic field vs current. To verify the stefans fourth power law of radiation by electrical method. For clarity, the original effect is sometimes called the ordinary hall effect to distinguish it from other hall effects. What is hall effect what are the applications of hall. Hall effect, development of a transverse electric field in a solid material when it carries an electric current and is placed in a magnetic field that is perpendicular to the current.
These steps are completely independent of the type of sample and quantitized to values he2m, where m is an integer. How can i use the hall effect experiment to measure the electron concentration in fto. Hall effect experiment utk department of physics and. It is a substance with conduction properties between metals and insulators. To determine the hall voltage developed across the sample material. Assume the conductor to have charge carrier of charge q can be either positive or negative. Which material conductor, semiconductor, insulator has been used to explain. It is numerically equal to hall electric field induced in. Measuring the hall effect is useful in determining many things, including the type of the semiconductor ptype or ntype, the charge of the carriers, the concentration, mobility, and band structure of the material.
Maybe the most commonly measured such effect is electron spin resonance esr, or epr for electron paramagnetic resonance. Polarimeter, a balance, measuring cylinder, beaker and a source of light. Mar 18, 2015 semiconductor hall effect basic concepts, numerical on hall effect, hall coefficient duration. Geometry of fields and sample in hall effect experiment. The hall effect sensing elements used in the sensor are temperature compensated. The voltage developed across the conductor is called hall voltage. The hall effect as presented by kishore padmaraju in experimental conjunction with greg smith alex pawlicki outline what is the hall effect.
Review and cite hall effect protocol, troubleshooting and other. In general, we ask our students to find the hall voltage and hall coefficient. Designing a gunn or impatt oscillator is not a trivial exercise, and the biasing is a pain. Two solenoids, constant current supply, four probe, digital gauss meter, hall effect apparatus which consist of constant current generator ccg, digital milli voltmeter and hall probe. The center of focus on this quiz and worksheet will be on concepts like polarizers, polarization, malus law, and light intensity.
Which material conductor, semiconductor, insulator has been. Investigating the hall effect in silver university of virginia. Hall effect experiment department of physics and astronomy. Name of experiment page no 1 to find the low resistance by careyfosters bridge. B in a zero magnetic field the current density vector j is parallel to the electric field e. These are a niche market, and the demand is not particularly high. Hall effect article about hall effect by the free dictionary. Keep the range switch of the gaussmeter in minimum range and adjust the zero adjustment such that the reading in the gaussmeter shows zero. Lab setup the setup is extremely vital to the success of the hall effect experiment.
Engineering physics viva and then there is physics. The hall effect and its applications sciencedirect. If the magnetic field is applied along negative zaxis, the lorentz force moves the charge carriers say electrons toward the ydirection. Sodium lamp for half shade polarimeter and ordinary bulb or mercury lamp for biquartz polarimeter. So for this purpose, the knowledge of the apparatus is must, like. Fabricate two semiconductor hall samples one ptype and one ntype and one copper sample. What is hall effect, what are the applications of hall effect, edc electrical engineering. The electric field, or hall field, is a result of the force that the magnetic field exerts on the moving positive or negative.
Hall effect experiment and 10 viva questions apni physics. Vtu physics experiment lab laser diffraction exam revision determination of wavelength of laser light using diffraction grating. All content provided on this blog is for informational purposes only. The owner will not be liable for any errors or omissions in this information nor for the availability of this information. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The hall effect in metals and semiconductors in this experiment, students learn about the classical hall effect which is the basis of most sensors used in magnetic field measurements. To calculate the hall coefficient and the carrier concentration of the sample material.
When a current carrying specimen is placed in a transverse magnetic field then a voltage is developed which is perpendicular to both, direction of current and magnetic. Click on the \digits option found on the right side, under the displays setting, to see a numerical output of the sensor after you press. Gokaraju rangaraju institute of engineering and technology. Esr is often measured in systems which not only have many electrons but also where the electrons interact. File type pdf hall effect experiment viva questions hall effect experiment viva questions thank you completely much for downloading hall effect experiment viva questions. If an electric current flows through a conductor in a magnetic field, the magnetic field exerts a transverse force on the moving charge carriers which tends to push them to one side of the conductor. Engineering physics laboratory 17 phyl 1727 201718 department of physics, c.
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