Statement-I : Linear momentum and moment of force have same dimensions.
Statement-II : Planck’s constant and angular momentum have same dimension.
In the light of the above statements, choose the correct answer from the options given below :
Correct Answer :
Statement-I is false while statement-II is correct
Solution :
The correct option/answer is: Statement-I is false while statement-II is correct.
Let's analyze both statements step-by-step using dimensional analysis.
Step 1: Analyze Statement-I
Statement-I states that linear momentum and moment of force have the same dimensions.
The formula for linear momentum () is:
where is mass and is velocity.
The dimensions of mass are and the dimensions of velocity are .
Therefore, the dimensional formula of linear momentum is:
The moment of force (torque, ) is given by:
where is distance and is force.
The dimensions of distance are and the dimensions of force are .
Therefore, the dimensional formula of moment of force is:
Comparing the two dimensional formulas:
Thus, Statement-I is false.
Step 2: Analyze Statement-II
Statement-II states that Planck’s constant and angular momentum have the same dimensions.
According to Planck's equation, the energy () of a photon is given by:
where is Planck's constant and is frequency.
So, .
The dimensions of energy are and the dimensions of frequency are .
Therefore, the dimensional formula of Planck's constant is:
The formula for angular momentum () is:
where is mass, is velocity, and is radius.
Therefore, the dimensional formula of angular momentum is:
Comparing the two dimensional formulas:
Thus, Statement-II is correct.
Conclusion:
Statement-I is false while statement-II is correct.
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