To determine the resistance per unit length of carey fosters bridge wire and specific resistance of the material of the given wire using carey fosters bridge. The circuit for careyfoster bridge is shown in figure below. What are the advantages that carey foster method has. Introduction the carey foster bridge is an electrical circuit that can be used to measure very small resistances.
G was calculated by following equations 9, 10 and 11. Position of null point changes on the wire when the resistance is connected in the outer gaps is interchanged. Carey foster bridge is very sensitive and we can even measure the decimal value of resistance. Carey foster bridgea meter long nichrome wire between thick copper strips fixed on wooden board, 1. Finally measuring the radius and length of the unknown resistance we can. To determine resistance per unit length of wire by using carey foster bridge. What is the conclusion for the wheatstone bridge experiment.
Carey foster bridge is specially used for the comparison of two equal resistances. Measurement of unknown resistance using careyfoster s bridge debangshu mukherjee bs. In this physics video in hindi for class 12 we explained the construction and working principle for carey foster bridge experiment. Carey fosters bridge, decimal resistance box, laclanche cell, galvanometer, thick copper strip, plug key, rheostat of nearly 10 ohm, given wire and connecting wires. Hi friends, this post provides an information about schering bridge which is used for measurement of capacitance. To find specific resistance of given wire using carey.
Kelvin bridge circuit kelvin double bridge electrical4u. Kelvin bridge circuit kelvin double bridge august 16, 2018 february 24, 2012 by electrical4u before we introduce kelvin bridge, it is very essential to know what is the need of this bridge, though we have wheatstone bridge which is capable of measuring electrical resistance accurately usually an accuracy of around 0. The schering bridge works on the principle of balancing the load on its arm. The wheatstone bridge is the fundamental bridge, but there are other modifications that can be made to measure various kinds of resistances when the fundamental wheatstone bridge is not suitable. To estimate strength of a current by using copper voltmeter. The thickedged areas are busbars of almost zero resistance. Schering bridge the schering bridge use for measuring the capacitance of the capacitor, dissipation factor, properties of an insulator, capacitor bushing, insulating oil and other insulating materials.
Carey foster bridge is the strategy utilized for estimation of medium opposition. Its operation is similar to the original potentiometer. It works on the same principle as wheatstones bridge, which consists of four resistances, p, q, r and s that are connected to each other as shown in the circuit diagram in figure 1. What are the advantages that carey foster method has compared. Tighten all the keys of the fractional resistance box before every measurement. Carey foster bridge is the method used for measurement of medium resistances. Download our viva questions on carey foster bridge experiment ebooks for free and learn more about viva questions on carey foster bridge experiment. The carey foster bridge in the picture is from denison university, and was made by leeds and northrup of philadelphia. Lab report bsc physics,1st years, chennai mathematical institute carey foster bridge aim. Resistance per unit length of the carey fosters bridge wire ohmcm. The bridge wire ef has a jockey contact d placed along it and is slid until the galvanometer g measures zero. Watch this video to know more about carey fosters bridge experiment. This channel covers theory classes, practical classes, demonstrations, animations, physics fun, puzzle and many more of the physics.
Point c can be located at any point along its branch until the deflection of the galvanometer is reduced to zero, thus indicating that the resistance along the top is the same as the bottom. We have just observed some essential strategies for estimating medium protections. Nov 29, 2012 anna university physics practical, carey foster bridge to determine specific resistance of the given coil. While recording the galvanometer null point, press the jockey firmly on the carey fosters bridge wire. Explain some of the advantages and limitations of a carey fosters bridge for measuring resistance. If the bridge is not balanced current will flow from d to b if v d v b i. In electronics, the carey foster bridge is a bridge circuit used to measure medium resistances. Measurement of low resistance using carey fosters bridge duration. A wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. Distinguish between a carey fosters bridge and a meter bridge.
Drag the resistor to the gap 2 and 3 of the carey fosters bridge. The carey foster bridge is an electrical circuit that can be used to. Link 6,link 7 a number of resistance measuring devices have been devised on the principle of wheatstone bridge. R is the unknown resistance under experiment, while s is a standard resistance. Carey foster bridge is exceptionally utilized for the correlation of two equivalent protections. The circuit for carey foster bridge is shown in figure below. A carey foster bridge is principally same as a meter bridge, which consists of four resistances p, q, r and x that are connected to each other as shown in figure 1. Carey foster bridge experiment related viva question.
Stewards and gees experiment learning objectives for inclass and out of class out of class at the end of watching the video the student should be able to. Download our carey foster bridge experiment related viva question ebooks for free and learn more about carey foster bridge experiment related viva question. Carey foster bridge specific resistance of the given. To find the low resistance by carey fosters bridge. The schering bridge use for measuring the capacitance of the capacitor, dissipation factor, properties of an insulator, capacitor bushing, insulating oil and other insulating materials. A meter bridge is the practical application of wheatstone bridge. To measure the horizontal components of earths magnetic field intensity using. Further the above relation is free from the end correction of the total length of the bridge wire. But i have a question which states that as we know, kelvin bridge is a modified wheatstone bridge. Hi friends, this post provides an information about schering bridge which is. Carey foster bridge, for measuring small resistances.
Clean the surface of the copper strip with the help of sand paper before the experiment. This is the simplest and the most basic bridge circuit used in measurement studies. In carey foster bridge this problem is over come by taking two standard resistances of the same order in addition so that they in series with the wire make the new ratio arms. Suppose we have to find the value of some unknown resistance of about ohms with a meter bridge wire of say 40 ohms resistance.
Describe a carey fosters bridge circuit, and explain how it can be used to measure an unknown resistance. The physics guide is a free and unique educational youtube channel. Drag the battery to space in between the two resistors. Meter bridge, post office box and carey foster bridge are instruments based on the principle of wheatstone bridge and are used to measure unknown. The carey foster bridge works on the principle of the wheatstone bridge potentiometerwhich can be used to measure fractional resistance. Aug 16, 2018 kelvin bridge circuit kelvin double bridge august 16, 2018 february 24, 2012 by electrical4u before we introduce kelvin bridge, it is very essential to know what is the need of this bridge, though we have wheatstone bridge which is capable of measuring electrical resistance accurately usually an accuracy of around 0. A meter bridge is an apparatus used to find the resistance of a coil. The difference in the value of resistance is equal to the resistances of the differences of bridge wire i. This can me measured using a carey foster bridge which is a bridge circuit used to measure low resistances, or to measure small differences between two large resistances. Measurement of unknown resistance using careyfosters bridge debangshu mukherjee bs. Carey foster bridge specific resistance of the given coil.
To define what is intensity of magnetic field and on what factors does it depend on recall level describe how the graph vary between distance and. A meter bridge, galvanometer, one way key, a resistance box, a battery jockey, unknown resistance wire about 1 meter long, screw gauge and connecting wires. Apr 14, 2017 describe a carey fosters bridge circuit, and explain how it can be used to measure an unknown resistance. Anna university physics practical, carey foster bridge to determine specific resistance of the given coil. We have already seen some basic methods for measuring medium resistances.
P and q are two nearly equal resistances inserted in gaps 1. The primary benefit of the circuit is its ability to provide extremely accurate measurements in contrast with something like a simple voltage divider. To determine the resis tance per unit length of carey fosters bridge wire and specific resistance of the material of the given wire using carey fosters bridge. Measurement of unknown resistance using careyfoster s bridge. Tighten all the electrical connections before measurement. Exp obj app galv conn des ef the strip in b kno resis cell galv on t. Analysis of the wheatstone bridge uk essays ukessays.
Care y foster s bridge, rheosta t, battery eliminator, copper strip, galvanometer, plug key, given wire whose specific resistance is to be determined. Free essays on physics speed of sound lab report through. Sep 09, 2006 in carey foster bridge this problem is over come by taking two standard resistances of the same order in addition so that they in series with the wire make the new ratio arms. Carey foster bridge electrical resistance and conductance. Measurement of unknown resistance using carey fosters bridge debangshu mukherjee bs. Bridge circuits 3 next we will use the ac bridge circuit shown to measure an unknown inductor with l somewhere between 15 and 25 mh. It mainly consists of four arms of resistance p, q. In this experiment, you will learn to use a carey fosters bridge to measure low resistance. The whitestone bridge is the fundamental bridge, but there are other modifications that can be made to measure various kinds of resistances when the fundamental wheatstone bridge is not suitable. Kelvin bridge, for measuring small fourterminal resistances. May 19, 2017 the physics guide is a free and unique educational youtube channel.
Wheatstones bridge in this circuit g is the galvanometer and e is a lead accumulator and k 1and k are the galvanometer key and accumulator key respectively. Care y fosters bridge, rheosta t, battery eliminator, copper strip, galvanometer, plug key, given wire whose specific resistance is to be determined. P and q are nearly equal resistances, forming the other half of the bridge. In the adjacent diagram, x and y are resistances to be compared. Show that when the bridge is balanced the resistance r4 and inductance l are given by r4 r2 r3 r1 and l r2r3 c. These books contain exercises and tutorials to improve your practical skills, at all levels.
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