The negative battery terminals are connected together and positive battery terminals are also connected together through a galvanometer as shown in the figure below.
Now again we adjust the sliding contact on the transistor to make the galvanometer current zero and once it becomes zero that is zero deflection is indicated in the galvanometer, we take the position of the sliding contact tip on the resistor scale and say it is L2.
Where r is the internal resistance of the battery cell. Another type is the linear slider potentiometer, which has a wiper which slides along a linear element instead of rotating. The transfer equation is similar to that of a low-pass filter.
This name is derived from the configuration used for many in the early days of electricity for measuring voltage.
Any potentiometer is constructed of the following parts: The terminals: As already discussed, the potentiometer has three terminals, two fixed and one variable. When the wiper is at terminal 1, R1 becomes zero and the voltage across the wiper is same as the supply voltage.
This type of potentiometer is mainly used to measure the voltage across a branch of a circuit, for measuring the internal resistance of a battery cell, for comparing a battery cell with a standard cell and in our daily life, it is commonly used in the equalizer of music and sound mixing systems.
How Does a Potentiometer Work? Virtually all preset potentiometers are of the linear type, but not all adjustable ones are.