Concepts Of Physics MCQ Edition [Volume 2]PhysicsThermal and Chemical Effects of Electric Current
An electrolysis experiment is halted, and the connections to the battery terminals are subsequently reversed.
Options
- AHeat will be generated at an increased rate.
- BThe electrolysis process will cease.
- CThe rate of material liberation will remain unchanged.
- DThe rate at which material is liberated at the electrodes will increase.
Correct answer
D. The rate at which material is liberated at the electrodes will increase.
Step-by-step solution
During electrolysis, a back EMF e is developed in the cell due to the accumulation of products at the electrodes, which opposes the applied EMF E . The effective EMF in the circuit is E - e , and the initial current is I₁ = E - e R , where R is the resistance of the circuit. When the battery terminals are reversed, the applied EMF E and the back EMF e act in the same direction. The new effective EMF becomes E + e . The new current in the circuit is I₂ = E + e R . Since I₂ > I₁ , the magnitude of the current in the