Question

When potential difference is applied across an electrolyte, then Ohm’s law is obeyed at
A) Zero potential
B) Very low potential
C) Negative potential
D) High potential

Answer 1

Hint: In order to describe electric circuits, Ohm’s law is used. According to Ohm’s Law, the current flowing through a conductor between any two points is directly proportional to the voltage applied across the two points and inversely proportional to the resistance applied across the circuit.
Complete step-By-Step Explanation:
Step I:
When voltage is applied to an electrolyte, the electrolyte will conduct electricity and electrolysis takes place. In the process of electrolysis, the substance either loses or gains electrons. The ions start dissociating. This means that the positive charge ions will move towards the negative electrode and negative charged ions move towards the positive electrode.
Step II:
 At low voltages, as the voltage increases the number of ions conducting also increases. This means that the current will rise making a non-linear form. After some time when the voltage reaches a certain value no more dissociation of the ions will occur.
Step III:
The electrolyte behaves as a conductor as strong electrolytes are good conductors of electricity and weak electrolytes are bad conductors of electricity and follows Ohm’s law. Thus at high voltages, an electrolyte obeys Ohm’s law.

$ \Rightarrow $Option D is the right answer.

Note:It is important to note that since the current rises in a non-linear form, the material is non ohmic. In the case of electrolytes, Ohm’s law is the resistance offered by the electrolyte. Also when the voltage across the circuit varies, the ratio of voltage to current must remain constant for Ohm’s law to apply otherwise if the voltage varies, then Ohm's law is not applicable.