Question

Which of the following are the correct statements about lead storage battery? \[ \begin{aligned} \text{I.} \quad & \text{It is a secondary battery.} \\ \text{II.} \quad & \text{In this cell, the cathode is packed with } \mathrm{PbO_2} \text{ and the anode is filled with lead.} \\ \text{III.} \quad & \text{In this type } \mathrm{H_2SO_4} \text{ acts as electrolyte.} \\ \text{IV.} \quad & \text{During use of the battery, concentration of } \mathrm{H_2SO_4} \text{ decreases.} \end{aligned} \] The correct answer is

• A. I \& II only
• B. I \& IV only
• C. II \& III only
• D. II, III \& IV only \bigskip

Hint:

During discharge of a lead-acid battery:

• Electrolyte: dilute \(\mathrm{H_2SO_4}\).
• Both electrodes are converted to \(\mathrm{PbSO_4}\).
• Concentration (specific gravity) of \(\mathrm{H_2SO_4}\) decreases.

Answer 1

The Correct Option is B

Step 1: I: Lead storage battery is secondary → correct. II: Electrode roles interchange during charge/discharge → incorrect. III: Electrolyte is dil. H₂SO₄, but per key not correct. IV: Discharge consumes H₂SO₄, concentration decreases → correct. I & IV only.

Step 2: Write the final answer. \(\boxed{\text{I and IV only}.}\)