Q. Consider the following pairs: | Lead | Element used in batteries |
| Mercury | Element used in thermometers |
| Cadmium | Element used in rechargeable batteries |
How many of the above pairs are correctly matched?
Answer:
All three pairs
Notes: - Lead: Indeed used in lead-acid batteries, which are commonly used in vehicles and backup power systems. Thus, this pair is correct.
- Mercury: Historically used in thermometers due to its high coefficient of expansion, allowing for accurate temperature readings. This pair is also correct.
- Cadmium: Used in nickel-cadmium (NiCd) rechargeable batteries, which are popular in portable electronics. This pair is correct as well.
Thus, all three pairs are correct.