Machine-translated by Google. Questions are authored in English.
Top

Discussion

In the equation A = B/CD2 , if B, C and D have the dimensions of inductive reactance, capacitive reactance and angular frequency respectively, then the dimensions of A are

  • A.\(M^{0}LT^{2}\)
  • B.\(ML^{0}T^{2}\)
  • C.\(M^{0}L^{0}T^{2}\)
  • D.\(M^{-1}L^{0}T^{-2}\)
  • E.\(M^{0}L^{0}T^{-2}\)

Answer: C

The dimensions of A are \(M^{0}L^{0}T^{2}\).

Inductive reactance and capacitive reactance are both measured in ohms, so B and C have the same dimensions and \(\frac{B}{C}\) is dimensionless. Angular frequency D has dimensions \(T^{-1}\). Hence

\[ \begin{aligned} [A] &= \frac{[B]}{[C][D]^{2}} = \frac{1}{T^{-2}} \\ &= M^{0}L^{0}T^{2} \end{aligned} \]

\(M^{0}L^{0}T^{-2}\) multiplies by \(D^{2}\) instead of dividing. The options with nonzero powers of M or L forget that the two reactances cancel completely.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.