primary and secondary cells

Question 1

Primary Cells

Answer 1

Non-rechargeable chemical cells

Question 2

Secondary Cells

Answer 2

Rechargeable chemical cells

Question 3

What is the main difference between primary and secondary cells

Answer 3

Primary Cells: Non-rechargeable. Once the chemical energy is used up, they must be discarded.

Secondary Cells: Rechargeable. Can be used repeatedly by reversing the chemical reaction using external electrical energy.

Question 4

How do terminal voltage and maximum current compare between primary and secondary cells

Answer 4

Terminal Voltage:

Primary: Typically 1.5V (e.g. zinc-carbon).

Secondary: Typically 1.2V – 3.7V (e.g. NiMH or Li-ion).

Maximum Current:

Primary: Lower, not suitable for high-drain devices.

Secondary: Higher, can power devices that require more current

Question 5

How do internal resistance and portability compare?

Answer 5

Internal Resistance:

Primary: Higher internal resistance.

Secondary: Lower, making them better for high-current use.

Portability:

Both types are portable, but secondary cells tend to be heavier due to more robust construction for recharging.

Question 6

Which type of cell is rechargeable?

Answer 6

Primary Cells: ❌ Not rechargeable. One-time use.

Secondary Cells: ✅ Rechargeable. Can be reused many times, saving cost and reducing waste.

Question 7

What are primary cells and give examples

Answer 7

Zinc-Carbon (e.g. remote controls)

Alkaline (e.g. wall clocks, toys)

Lithium (Primary) (e.g. smoke detectors)

Silver Oxide (e.g. watches, hearing aids)

Question 8

What are secondary cells and give examples

Answer 8

Nickel-Cadmium (NiCd) – power tools

Nickel-Metal Hydride (NiMH) – digital cameras

Lithium-Ion (Li-ion) – phones, laptops

Lead-Acid – car batteries