Ans: It is called a potentiometer because it measures the potential difference between any two points in an electric circuit. Let ‘I’ be the steady current flowing through the wire. // --> // -->, GD&T Training Geometric Dimensioning Tolerancing. large e.m.f. the internal resistance of the cell using this formula. Hence, Lρ/A = K. V = KL. E1 is connected to end A and a negative terminal is connected to jockey through the galvanometer. By sliding the Jockey along the wire, a point of contact P1 for which the galvanometer shows zero deflection is found. With ⍴ and A constant, I is also constant for a rheostat. 1.Cell A device to maintain a steady current in an electric circuit is electrolytic cell. E is connected to the end A of the potentiometer wire. U = f (x) + a + b the deviation is referred to as conformity. Thus, the resistance of a wire of length ‘RAP’ is given by. A potentiometer is a manually adjustable, variable resistor with three terminals. E1, e.m.f. The length of wire AP = l 1 is measured. E2 be the e.m.f.’s of the two cells to be compared by using the end of potentiometer wire where positive terminal of the battery (driving cell) | Feedback The positive consists of a uniform wire AB several meters long. I= (V)/(R 1 + R 0 /2) The voltage V 1 taken from the potentiometer will be the product ofcurrent I and resistance R 1, V 1 = I R 1 = (2V)/ (2R 1 R 0) x R 1. Thus it measures the e.m.f. terminal of the cells whose e.m.f. Thus knowing R, l and l1 we can calculate the value of r i.e. A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. The current through a voltage-divider circuit such as the one in Fig. Potentiometer. On closing, the Potential gradient is calculated as K = V/L, where V is the voltage across the potentiometer wire and the L is the length of the wire in the potentiometer. By closing the key K1 current is passed through the potentiometer wire so that uniform potential gradient is produced along the wire. Derivation : From the figure, connect points 1 and 3 together with balance point at point N1, where AN 1 = l 1 Now connect points 2 and 3 together with balance point at point N 2, where AN 2 = l 2. A voltmeter is portable while potentiometer is non-portable. Syllabus. (Derivation not required). Potentiometer Circuit Diagram Now a closer look into the figure, we can see that at the current position of wiper, there are two resistive paths just like the resistor is split into two resistors. Question Papers 245. Following is the derivation of used to explain the potentiometer working principle: \(V=IR\) (Ohm’s law) Where, I: current. Now, R = ρL/A and V = I (pL/A) Where ρ is resistivity and A is the cross-sectional area. Where there is a linear relationship, deviation is referred to as linearity. CISCE ISC (Science) Class 12. I didn't bother to solve simultaneous equations, I just whacked the formula into a spreadsheet and varied R1 until I got the required output voltage, so there are no further steps. The length of wire AP = l1 is measured. Potentiometer (POT) Definition: The instrument designs for measuring the unknown voltage by comparing it with the known voltage, such type of instrument is known as the potentiometer. The length of the wire AP1 = l is measured. document.write(''); A potentiometer can be used to measure extremely small p.d. are connected together. Next let the points 2 and.3 be connected together.