Physical World Units and Measurements - Result Question 20
21. The dimensions of Planck’s constant are same as
(a) energy
[2001]
(b) power
(c) momentum
(d) angular momentum
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Answer:
Correct Answer: 21. (d)
Solution:
- (d) We know that $E=h v$
$h=\frac{E}{v}=\frac{[ML^{2} T^{-2}]}{[T^{-1}]}=[ML^{2} T^{-1}]$
Angular momentum $=I \omega$
$=[ML^{2}][T^{-1}]=[ML^{2} T^{-1}]$
(c) Force has dimension $[MLT^{-2}]$ while impulse has dimension $[MLT^{-1}]$, both have different dimensions.
