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Given below are two statements:Â
Statement (I) : Planck's constant and angular momentum have the same dimensions.
Statement (II) : Linear momentum and moment of force have the same dimensions. In light of the above statements, choose the correct answer from the options given below :
We need to check the dimensional correctness of both statements.
Statement (I): Planck's constant and angular momentum have the same dimensions.
Planck's constant $$h$$ has the relation $$E = h\nu$$, so:
$$[h] = \frac{[E]}{[\nu]} = \frac{ML^2T^{-2}}{T^{-1}} = ML^2T^{-1}$$
Angular momentum $$L = mvr$$, so:
$$[L] = M \cdot LT^{-1} \cdot L = ML^2T^{-1}$$
Both have the same dimensions $$ML^2T^{-1}$$. Statement (I) is true.
Statement (II): Linear momentum and moment of force have the same dimensions.
Linear momentum $$p = mv$$:
$$[p] = MLT^{-1}$$
Moment of force (torque) $$\tau = r \times F$$:
$$[\tau] = L \cdot MLT^{-2} = ML^2T^{-2}$$
The dimensions are different: $$MLT^{-1} \neq ML^2T^{-2}$$. Statement (II) is false.
Therefore, Statement I is true but Statement II is false.
The correct answer is Option A.
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