Wheatstone bridge is the most general and fundamental bridge of difference type measurement in circuit. Carey foster bridge specific resistance of the given coil. In excess, we claculate the resistance of the wire used in the bridge and hence get the endcorrections using the carey foster bridge to get a better value of resistance than with the metre bridge. Carey foster bridge is the strategy utilized for estimation of medium opposition. Measurement of the magnetic field along the axis of a current carrying circular coil to verify biot savart law and to estimate the radius of the coil. Carey foster bridge is the method used for measurement of medium resistances. Wheatstone bridge measures every type of impedance high or low. Sep 07, 2017 carey foster bridge bsc mathematics lectures 1st year,bsc mathematics syllabus,bsc mathematics classes,bsc mathematics 2nd year,bsc mathematics lectures in t. Position of null point changes on the wire when the resistance is connected in the outer gaps is interchanged. Carey foster bridge specific resistance of the given. The carey foster bridge in the picture is from denison university, and was made by leeds and northrup of philadelphia. Anna university physics practical, carey foster bridge to determine specific resistance of the given coil. The connections of carey foster slide wire bridge are shown in the below figure. Carey foster bridge is very sensitive and we can even measure the decimal value of resistance.
Suppose we have to find the value of some unknown resistance of about ohms with a meter bridge wire of say 40 ohms resistance. Distinguish between a carey foster s bridge and a meter bridge. If you know are looking for the lp pdf as the unconventional of reading, you can find here. Resistance per unit length of the carey foster s bridge wire ohmcm 2. P and q are two nearly equal resistances inserted in gaps 1. To determine the resolving power of a telescope and then verify its expression. To find specific resistance of given wire using carey fosters.
A meter bridge is an apparatus used to find the resistance of a coil. To determine the resistance per unit length of carey foster s bridge wire and specific resistance of the material of the given wire using carey foster s bridge. First year first semester humta humanitiesa english 2 pdsweek 50 marks. Theory both the metre bridge and the carey foster bridge are a. The circuit for carey foster bridge is shown in figure below. The aim of the experiment is to determine the resistance per unit. Determination of refractive index of the material of a prism using spectrometer and sodium light 35 6. The carey foster bridge is used to measure the difference between two nearly equal resistances and knowing the value of one, the other can be calculated. Carey foster bridge electrical resistance and conductance. Q3 which apparatus are you using to determine the resistance of the wire in your experiment. While performing this experiment, you will balance the carey foster bridge by a null deflection method using a galvanometer.
Carey foster s method17 puts a slide wire between the standard resistance. To determine the resistance per unit length of a carey foster s bridge wire and resistivity of. 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. To find specific resistance of given wire using carey. Kelvin bridge circuit kelvin double bridge electrical4u. Care y foster s bridge, rheosta t, battery eliminator, copper strip, galvanometer, plug key, given wire whose specific resistance is to be determined. The circuit for carey foster bridge is appeared in. Why barbara spear webster given a in memory of on murder she wrote. Measurement of unknown resistance using carey fosters bridge debangshu mukherjee bs. Experiment 4 relation between wavelength and frequency of stationary waves experiment 5 determination of youngs modulus of a material by bending of beams experiment 6 measurement of low resistance using carey foster s bridge experiment 7 variation of thermoe. What are the advantages that carey foster method has compared. What are the advantages that carey foster method has. Carey foster bridge specific resistance of the given coil duration. The thermometer comprises a length of fine platinum wire of about 2 ohms resistance, wound noninductively on a mica frame and soldered to stout copper leads.
To find specific resistance of given wire using carey fosters bridge. Download ebook engineering physics lab viva questions viva disclaimer. Name of experiment page no 1 to find the low resistance by careyfosters bridge. In the carey foster bridge s 1st experiment to determine unknown resistance per unit length of a wire, we use a copper strip which has no resistance. Why are you using the carey foster s bridge instead of meter bridge. Acceleration due to gravity g by using bar pendulum aim. To determine resistance per unit length of wire by using carey foster bridge. Theorey and demonstartion platinum resistance thermometer nptel. 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.
Programme department of physics birla institute of technology. Carey foster slidewire bridge the carey foster bridge is used for measuring the low resistance or for the comparison of two nearly equal resistances. Name of experiment page no 1 to find the low resistance by carey foster s bridge. The wheatstone bridge can still be used to measure very low values of resistances. First we use the copper strip in one end and take reading, after that we use it one the other end and take reading. The working principle of the carey foster bridge is similar to the wheatstone bridge. To determine the value of acceleration due to gravity g at the surface of earth by using bar pendulum. In electronics, the carey foster bridge is a bridge circuit used to measure medium resistances, or to measure small differences between two large resistances. Describe a carey foster s bridge circuit, and explain how it can be used to measure an unknown resistance. Specific resistance is a measure of the potential electrical resistance of a conductive material. Experiment 6 to determine the resistance per unit length of a carey foster s bridge wire and also to find out the specific resistance of a given wire. The circuit for careyfoster bridge is shown in figure below.
He first described it in his 1872 paper on a modified form of wheatstones bridge, and methods of measuring small. To study the variation of magnetic field along the axis of current carrying circular coil and then to estimate the radius of the coil. The working principle of the ballistic galvanometer is very simple. In excess, we claculate the resistance of the wire used in the bridge and hence get the endcorrections using the careyfoster bridge to get a better value of resistance than with the metre bridge. The carey foster bridge is often used for the measurement of very low resistances, although it can be used to find, for example. Physics experiment lab laser diffraction exam revision determination of wavelength of laser light using diffraction grating. Resistances p and q are first adjusted so that the ratio p q is approximately equal to the ratio rs. This is the simplest and the most basic bridge circuit used in measurement studies. A slidewire of length l being included bet ween r and s as shown. Carey foster bridge is specially suited for the comparison of two nearly equal resistances. 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.
Measurement of unknown resistance using careyfoster s bridge. Measurement of mechanical equivalent of heat by electrical method 29 5. R is the unknown resistance under experiment, while s is a standard resistance. To determine the resistance per unit length of a carey fosters bridge wire and resistivity of a given wire. Resistance of the given wire ohm viva voce q1 what is your experiment. In this experiment, you will learn to use a carey fosters bridge to measure low resistance. To estimate strength of a current by using copper voltmeter. 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. Hi friends, this post provides an information about schering bridge which is used for measurement of capacitance. Theory both the metre bridge and the careyfoster bridge are a simpli. Engineering physics practical experiments viva questions. The galvanometer which is used for estimating the quantity of charge flow through it is called the ballistic galvanometer. To determine the specific resistance of a given wire using carey foster s bridge.
Carey foster bridge is exceptionally utilized for the correlation of two equivalent protections. To determine the resis tance per unit length of carey foster s bridge wire and specific resistance of the material of the given wire using carey foster s bridge. Carey foster bridge, for measuring small resistances. Aug 27, 2012 in the carey foster bridges 1st experiment to determine unknown resistance per unit length of a wire, we use a copper strip which has no resistance.
This can me measured using a carey foster bridge which is a bridge circuit used to measure. And it is used to measure the low resistance of less than 1ohm, my question is, can it not be used for measuring medium resistance as wheatstone bridge do. 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. We have just observed some essential strategies for estimating medium protections. Finally measuring the radius and length of the unknown resistance we can. Who or what part did barbara spear webster play on murder she wrote.
First year be students 2017 birla institute of technology. He first described it in his 1872 paper on a modified form of wheatstones bridge, and methods of measuring small resistances telegraph engineers journal, 1872. It was invented by carey foster as a variant on the wheatstone bridge. The wheatstone bridge has many uses in electronic circuits other than comparing an unknown resistance with a known resistance. The wheatstone bridge was originally developed by charles wheatstone to measure unknown resistance values and as a means of calibrating measuring instruments, voltmeters, ammeters, etc, by the use of a long resistive slide wire although today digital multimeters provide the simplest way to measure a resistance. Explain some of the advantages and limitations of a carey fosters bridge for measuring resistance. 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. But i have a question which states that as we know, kelvin bridge is a modified wheatstone bridge. Pdf physics experiment ritesh raj keshari academia. To determine the resistance per unit length of a carey fosters bridge wire and then to find the resistivity of the material of a given wire 23 4. Explain some of the advantages and limitations of a carey foster s bridge for measuring resistance.
To determine the resistance per unit length of a carey foster s bridge wire and then to find the resistivity of the material of a given wire 23. Carey fosters bridge setup experiment physics lab equipment. Hi friends, this post provides an information about schering bridge which is. The difference in the value of resistance is equal to the resistances of the differences of bridge wire i. Introduction the carey foster bridge is an electrical circuit that can be used to measure very small resistances.
We have already seen some basic methods for measuring medium resistances. When used with operational amplifiers, the wheatstone bridge circuit can be used to measure and amplify small changes in resistance, r x due, for example, to changes in light intensity as we have seen above. Carey foster bridge is specially used for the comparison of two equal resistances. Measurement of unknown resistance using carey foster s bridge debangshu mukherjee bs. For showing the principles of platinum resistance thermometry and for accurate temperature measurement using a bridge method such as cary foster bridge. It mainly consists of four arms of resistance p, q. Which is an advantage and hence it can conveniently used to measure a given resistance. In this bridge, the end resistances are eliminated in calculation. Name of the experiment to determine the dispersive power of a material of prism using spectrometer. Measurement of unknown resistance using careyfosters bridge debangshu mukherjee bs. 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. Apr 14, 2017 describe a carey fosters bridge circuit, and explain how it can be used to measure an unknown resistance. Kelvin bridge, for measuring small fourterminal resistances.
We do not intend to harm the feelings of any student, teacher, faculty or any part of the society through the. Distinguish between a carey fosters bridge and a meter bridge. Experiment 6 to determine the resistance per unit length of a carey fosters bridge wire and also to find out the specific resistance of a given wire. Nov 29, 2012 anna university physics practical, carey foster bridge to determine specific resistance of the given coil. Video tutorial experiment 7 to plot graph showing the variation of magnetic field with distance along the axis of a circular coil carrying current, and hence estimate the radius.
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