A meter bridge is the practical application of wheatstone bridge arrangement as shown in figure below. The resistance rs is generally a standard resistance that is variable and made with great precision so that its value is well known, and ru is an unknown resistance. There are two gaps, one on the left side and the other on the right side, in the horizontal part of the metallic strip where two resistors, one of which is known and the other unknown are attached. The galvanometer g is a sensitive current sensing meter. A one meter length wire, made of an alloy that has a much higher resistance than that of a similar copper wire, is strung between points a and d, forming the lower part of the circuit. A meter bridge also called a slide wire bridge is an instrument that works on the principle of a wheatstone bridge. Meterbridge slide wire bridge meter bridge is based on the principle of wheatstone bridge and it is used to find the resistance of an unknown conductor or to compare two unknown resistance. It can be also used to calculate the effective series and parallel equivalent of resistances.
A wheatstone bridge is a kind of electrical circuit used in measuring an electrical resistance, which is unknown by. Theory the purpose of this experiment is to measure the electromotive force emf and internal resistance of a dry cell. Finding the resistance of a given wire using meter bridge. Aim to find the resistance of a given wire using meter bridge and hence determine resistivity of its material apparatus. To determine the resistance of a given wire using a metre bridge and. Why are the resistances used in a resistance box is like 1,2,2,5,10,20,20. Meter bridge consists of a 1 meter long standard resistance wire of uniform crosssection held taut between two ends of metallic strip bent at right angle at the ends.
Measure the unknown resistances x1and x2 separately using the procedure explained in experiment 2, after making the suitable connections as done in experiment 2. Various forms of the wheatstone bridge are used to accurately determine the value of an unknown resistance, capacitance or inductance. A meter bridge slide wire bridge, a lecranche cell, a galvanometer, a resistor, a jockey, a one way key, a resistance wire, a screw gauge, a meter scale, a set of square, connecting wire, a piece of sand paper. To verify the laws of combination series of resistance. To verify the laws of combination series of resistances. When rs is adjusted until the voltage difference v in fig. Metre bridge, a wire about 1m long of material whose specific resistance is to be determined, a resistance box, a rheostat, galvanometer, a jockey, oneway key, a cell or battery eliminator, thick connecting wires, sand paper, screw gauge. How does the resistance of a wire depend on its dimensions. 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. What happens to the resistivity of a wire when it is doublefolded. Measurement of inductance by hays bridge apparatus used. The two ends of the wire are attached to ter minals a and c. Aim to verify the laws of combination parallel of resistances using a metre bridge. The terminal voltage of a cell is the potential difference between its terminals.
Ab is a uniform wire 100 cm1m long, stretched in two segments of 50 cms. Students correlate the principle of wheatstones bridge with metre bridge experiment. To verify the laws of combination of resistances series and parallel using a metre bridge. A metre bridge, a sensitive galvanometer, two different resistances carbon or wirewound resistors, a resistance box, a jockey, a rheostat, a plug key, a cell or battery eliminator, thick connecting wires and a piece of sand paper. The four resistances are connected to each other as shown and if the bridge is in balanced state, i. Theory both the metre bridge and the careyfoster bridge are a simpli. Viva voce questions from ohms law, metre bridge, potentiometer, galvanometer and other experiments from electricity and magnetism. To verify the laws of combination of resistances using a. To find resistance of a given wire using metre bridge physics.
Meter bridge series and parallel circuits capacitance. Solution state any two possible sources of errors in meter bridge experiment concept. Where r is the resistance from resistance box in the. This video explains how to find the resistance of a given wire using a metre bridge and hence determine the specific resistance of. Two gaps are formed on it by using thick metal strips in order to make the wheat stones bridge. The metre bridge consists of a straight uniform resistance wire ab, 1 m long, stretched over a boxwood scale graduated in millimetres and mounted on a board fig. Its operation is similar to the original potentiometer. Repeat steps 2 6 by connecting resistances r 1 and r 2 in parallel. The hays bridge differs from maxwells bridge by having resistor r1 in series. Science physics current electricity numerical problems on wheatstones metre bridge 01 in this article and the next article, we shall study numerical problems based on wheatstones metre bridge. The meter bridge uses the same principle as the wheatstone bridge. Name of the apparatus quantity 1 lab trainer kit 1 2 multimeter 1 3 unknown inductor 1 theory. A resistance wire is laid along the length of a metre rule and contact with the wire is made through a galvanometer by a slider. Theorems and the wheatstone bridge figure 4 example circuit for prelab analysis.
Metre bridgeresistance of a wire meity olabs youtube. This video explains how to find the resistance of a given wire using a metre bridge and hence determine the specific resistance of its materials. In above figure ac is a 1m long wire made of maganin or constanan having uniform area of cross. If a parallel circuit is connected to the wire with a sliding contact, galvanometer, and standard. Physics forums the fusion of before reading your post, i had never seen a wheatstone bridge referred to as a meter bridge. As the bridge is brought nearer the final balance, bare copper wire around the terminals.
The practical diagram is shown in the below figure. Aim to find the resistance of a given wire using meter bridge and hence determine resistivity of its material. It is used to find the unknown resistance of the material. In a metre bridge experiment, with the resistance r 1 in the left gap and a resistance x in the right gap, the null point is obtained at 40 cm from the left end. Wheatstone bridge working principle your electrical guide.
It works in the principle of the balanced condition of wheatstone bridge. Meter bridge determination of specific resistance experiment edunovus online smart practicals. Physics practical class 12 all study guide at one place. This is an equally safe and accurate method for balancing the bridge. It consists of a rigid base containing a meter stick and series of terminals with. To verify the laws of combination of resistances in series using a meter bridge. Below is an experiment on how to find the resistance of a given wire using metre bridge and to determine the resistivity of its material. A meter bridge is an electric device used for measuring an unknown resistance. Meter bridge study material for iit jee askiitians. It is constructed on the principle of wheatstone bridge. Determination of the specific resistance of a wire using a meter bridge. A meter bridge slide wire bridge, a lecranche cell, a galvanometer, a resistor, a jockey, a one way key, a resistance wire, a screw gauge.
Thick metal strips bent at right angles ar e used to pr ovide two gaps e and f to connect resistors forming a wheatstones fig. A meter bridge is used in finding the unknown resistance of a conductor as that of in a wheatstone bridge. Two terminals at either end are connected to the meter stick by a lowresistance metal strip. Meter bridge experiment physics forums the fusion of. Zero error in measuring instruments voltmeter, ammeter, metre. To find r 1 and r 2 proceed same way as in experiment 1. Repeat the experiment for four more values of resistances r. Apparatus a metre bridge, a leclanche cell battery eliminator, a galvanometer, a resistance box, a jockey, two resistance wires or two resistance coils known resistances, a set square. A metre bridge is a simple type of potentiometer which may be used in school science laboratories to demonstrate the principle of resistance measurement by potentiometric means. Finding the resistance of a given wire using meter bridge and hence.
If you selected, single, then drag the battery and the resistance box shown on the side bar menu near to the metre bridge using your mouse. Meter bridge is a sensitive device based on the principle of wheatstones bridge, for the determination of the resistance of a conductor wire. Meter bridge formula and finding the values of unknown resistance. In this experiment, the potentiometer consists of a long uniform wire with a constant current in it and a method for. With the resistance r 2 in the left gap and the same resistance x in the right gap, the null point is obtained. Meter bridge is based on the principle of wheat stone bridge and it is used to find the resistance of an unknown conductor or to compare two unknown resistance.
Metre bridge it consists of one metre long constantan wire ac of uniform crosssectional ar ea mounted on a wooden board with a scale fig. Metre bridge law of combination of resistors procedure. The meter bridge consists of a wire of 100 cm, a scale, one unknown resistor, one known resistor or a resistance box, a galvanometer and a jockey. The emf of a cell may be defined as the terminal voltage of the cell when not under load, that is. To verify the laws of combination parallel of resistances using a metre bridge. Ac is a 1 meter wire of manganin or constantan which is fixed along a scale on a wooden base. Figure below shows a schematic diagram of a meter bridge. Cbse,class 12th,physics practical file readings tuesday, 21 january 2014.
In this experiment, a wheatstone bridge will be used for the following purposes. A meter bridge is an electrical instrument which is used to determine the resistance of a given conductor. Drag one of the wires to the right gap of the metre bridge. The device consists of a meter long wire ac of uniform crosssection and of low temperature coefficient of resistance. To find the resistance of the given wire using meter bridge and hence determine the specific resistance of its material. Precautions when using a metre bridge 1 the value of the known resistance s should be chosen so that the balance point comes somewhere on the middle third of the wire, i. The area of crosssection of the wire is the same at all places.
Scribd is the worlds largest social reading and publishing site. Experiment we will use a slidewire wheatstone bridge, in which the two resistors r1 and r2 are two portions of a single, uniform nicr wire. The metre bridge is operates under wheatstones principle. Devise an experiment to determine the resistance of i 25 cm length ii 60 cm length of a given resistance wire, using the metre bridge. A meter bridge, galvanometer, one way key, a resistance box, a battery jockey, unknown. To verify the laws of combination series of resistances using a metre bridge. The meter bridge is a device for measurement of resistance using the principle of wheatstone network. Then, the voltage vs can be gradually increased from zero to some maximum voltage, with repetitive attempts to balance the bridge at intermediate values of voltage. The primary benefit of the circuit is its ability to provide extremely accurate measurements in contrast with something like a simple voltage divider. To measure the emf of an unknown cell using a potentiometer. State any two possible sources of errors in meterbridge. Meter bridge formula and finding the values of unknown.
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