Answer
Verified
399.3k+ views
Hint: A potentiometer consists of a galvanometer, a variable resistance, a battery. In the circuit for the comparison of the emfs of the two cells, the circuit will comprise two cells as well.
Complete step by step solution:
Figure: A potentiometer circuit designed for comparing emfs of two cells.
In the above figure, the wires run from point A to point C. The small vertical portions are metal strips connecting various sections of the wire. B is the battery, R is the variable resistance (the arrow indicates variable resistance) which is also known as the rheostat. e and f are the two cells whose emfs are to be compared. G is the galvanometer and N and M are the two points to which the galvanometer jockey is connected. The points marked 1,2 and 3 form a way key. K is the key of the circuit.
Working formula:
If ${{\varepsilon }_{1}}$ is the emf of cell e and ${{\varepsilon }_{2}}$is the emf of cell f, then the formula for comparison is given as,
$\dfrac{{{\varepsilon }_{1}}}{{{\varepsilon }_{2}}}=\dfrac{{{l}_{1}}}{{{l}_{2}}}$
where, ${{l}_{1}}$ and ${{l}_{2}}$ are the distances of point N and M respectively from point A.
Additional Information:
There is also an arrangement of potentiometers for determining the internal resistance of a cell, where we do not need to incorporate the two cells.
Note: Students must note that ${{l}_{1}}$ and ${{l}_{2}}$ are the distances from point A and not from the galvanometer G or point C. And to represent the variable resistance, it is always necessary to give the arrow across the resistance, else it does not represent a variable resistance.
Complete step by step solution:
Figure: A potentiometer circuit designed for comparing emfs of two cells.
In the above figure, the wires run from point A to point C. The small vertical portions are metal strips connecting various sections of the wire. B is the battery, R is the variable resistance (the arrow indicates variable resistance) which is also known as the rheostat. e and f are the two cells whose emfs are to be compared. G is the galvanometer and N and M are the two points to which the galvanometer jockey is connected. The points marked 1,2 and 3 form a way key. K is the key of the circuit.
Working formula:
If ${{\varepsilon }_{1}}$ is the emf of cell e and ${{\varepsilon }_{2}}$is the emf of cell f, then the formula for comparison is given as,
$\dfrac{{{\varepsilon }_{1}}}{{{\varepsilon }_{2}}}=\dfrac{{{l}_{1}}}{{{l}_{2}}}$
where, ${{l}_{1}}$ and ${{l}_{2}}$ are the distances of point N and M respectively from point A.
Additional Information:
There is also an arrangement of potentiometers for determining the internal resistance of a cell, where we do not need to incorporate the two cells.
Note: Students must note that ${{l}_{1}}$ and ${{l}_{2}}$ are the distances from point A and not from the galvanometer G or point C. And to represent the variable resistance, it is always necessary to give the arrow across the resistance, else it does not represent a variable resistance.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Assertion The resistivity of a semiconductor increases class 13 physics CBSE
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
The branch of science which deals with nature and natural class 10 physics CBSE
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
Trending doubts
How do you solve x2 11x + 28 0 using the quadratic class 10 maths CBSE
Which type of bond is stronger ionic or covalent class 12 chemistry CBSE
What organs are located on the left side of your body class 11 biology CBSE
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Difference Between Plant Cell and Animal Cell
How fast is 60 miles per hour in kilometres per ho class 10 maths CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
When people say No pun intended what does that mea class 8 english CBSE