Which cell is used in automobiles and inverters?

The correct answer is Option (3) → Lead storage cell

Lead storage cell produces electricity continuously.

Option-wise

Option 1: Mercury cell

A mercury cell is a primary cell.

• Non-rechargeable
• Small size
• Supplies low current
• Used in watches, calculators, hearing aids

Vehicles need repeated charging from alternator - mercury cell cannot be recharged. So it cannot be used.

Option 2: Dry cell

Dry cells (Leclanché cells):

• Primary cells
• Low capacity
• Cannot provide large starting current needed to start engines
• Used in torches, remotes, toys

Cars need very high current briefly to crank the engine - dry cells cannot deliver that.

Option 3: Lead storage cell

Lead storage cell (lead-acid battery):

• Secondary (rechargeable)
• Can deliver very high current
• Works through reversible reactions:

Uses:

• Automobiles (starting, lighting, ignition)
• Inverters (power backup)

This exactly matches the need.

Option 4: Fuel cell

Fuel cells:

• Need continuous fuel supply ($H_2, O_2$)
• Used in spacecraft and experimental vehicles
• Not conventional storage batteries

Home inverters and cars do not operate on fuel cells in standard systems.