Question

The resistance of a cell does not depend on
A Current drawn from the cell
B Temperature of electrolyte
C Concentration of electrolyte
D The e.m.f of the cell

Answer 1

Hint:In the given question we need to find out on what factors internal resistance depends (inside the cell). Whenever there is circuit close and the current state flowing outside the cell by the process of discharging inside the cell. During this discharge the moving ions experience resistance and thus the left amount of voltage remains less as compared to voltage present inside the cell.





Complete answer:

The resistance of the cell is known as internal resistance which is provided by the electrolyte material inside the cell when potential difference started to decreases (or can say current started to flow) and the resistant which is experienced by the flow of current is known as external resistance which is due offered by the path which is followed by the current outside the cell. The external resistance is represented as R and internal resistance is represented as r. And both are directly proportional to area and inversely proportional to length. Now if current in the circuit (containing cell, a energy source and wire, a conductor) flow resistance will be experienced (R + r) and voltage decreases (terminal voltage) as compared to voltages applied (e.m.f).

Now if we talk about option first then the internal resistance depends on current so it could not be a correct option as with increase of current resistance of system decreases and vice-versa. With increase of temperature internal resistance decreases and if concentration of electrolyte increases then ions also increases thus, resistance will also increase.

Whereas the electromotive force (EMf) is a potential difference when there is no current inside the circuit. As with the flow of charges current resistance varies but if there is no current thus there will be no internal resistance thus we can say internal resistance is independent e.m.f.
Thus, the correct option is D.



Note:The e.m.f is defined as force (electromotive force) as per its name but in actual it is a potential difference when there is no current flowing through circuit and as soon as we close the circuit the voltage inside the cell started to drop because of internal resistance and thus the resultant voltage is always less than the applied voltage (through cell) because some voltage (terminal voltage) lost inside the cell such as V = e + Ir
Where V is terminal voltage, e is e.m.f or actual voltage applied through circuit, I is current flow through circuit and r is internal resistance.