Which of the following pairs is NOT correctly matched? [Quantity – S.I. Unit]
- (a) Activity of radio-active substance – Curie
- (b) Power of lens – Diopter
- (c) Heat – Joule
- (d) Pressure – Pascal
- A(a)
- B(b)
- C(c)
- D(d)
Show answer and explanation
Correct answer: (a) (a)
Explanation
The SI unit of activity of a radioactive substance is the becquerel (Bq), not the curie, so pair (a) is wrong.
Power of a lens = dioptre (D), heat = joule (J), and pressure = pascal (Pa) are all correctly matched.
The curie is an older non-SI unit of radioactivity.