Identify the incorrect one:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Power: Weber
Each option pairs a physical quantity with an SI unit. The unit of power (work done per second) is the watt (1 W = 1 J/s); the weber is the SI unit of magnetic flux. So this pair is the incorrect one.
The other pairs
Option (1) Force: Newton — correct; 1 newton is the force that gives 1 kg an acceleration of 1 m/s2.
Option (2) Energy: Joule — correct; 1 joule is the work done by a force of 1 N moving through 1 m.
Option (4) Pressure: Pascal — correct; 1 pascal is a force of 1 N acting on an area of 1 m2.