Physics Circle home Student Login

Home›Chapters›Units, Dimensions and Measurement PYQs›Applications of Dimensional Analysis›Question 67

NEET 2016 (Phase 2) · Applications of Dimensional Analysis

Applications of Dimensional Analysis question from NEET 2016 (Phase 2)

Q67NEET 2016 · PHASE 2Medium

Applications of Dimensional Analysis

Planck's constant (h), speed of light in vacuum (c) and Newton's gravitional constant (G) are three fundamental constants. Which of the following combinations of these has the dimension of length?

Show answer and solution

Answer: (a)

  1. [hG]=ML2T−1⋅M−1L3T−2=L5T−3[hG] = ML^2T^{-1}\cdot M^{-1}L^3T^{-2} = L^5T^{-3}, so [hG]=L5/2T−3/2[\sqrt{hG}] = L^{5/2}T^{-3/2}.
  2. [c3/2]=L3/2T−3/2[c^{3/2}] = L^{3/2}T^{-3/2}.
  3. hGc3/2\dfrac{\sqrt{hG}}{c^{3/2}} has dimension LL.
  4. So the answer is (a).
Report a mistake

More questions on Applications of Dimensional Analysis