JEE MainPhysicsUnits and Dimensions
Which of the following sets of physical quantities cannot be chosen as a system of fundamental quantities?
Options
- ADensity, Velocity, Area
- BForce, Velocity, Acceleration
- CMomentum, Force, Time
- DEnergy, Velocity, Time
Correct answer
C. Momentum, Force, Time
Step-by-step solution
For a set of physical quantities to be chosen as a system of fundamental quantities, they must be dimensionally independent. This means no quantity in the set can be expressed as an algebraic combination of the other quantities in the set. Let us check the set containing Momentum ( p ), Force ( F ), and Time ( t ). From Newton's second law, Force is the rate of change of momentum: F = p t . Dimensionally, this gives [p] = [F][t] . Since momentum can be completely expressed in terms of force and time, the three quan