If 'E', 'M', 'L' and 'G' denote energy, mass, angular momentum and constant of gravitaion respectively then…

If 'E', 'M', 'L' and 'G' denote energy, mass, angular momentum and constant of gravitaion respectively then $\left(\frac{\mathrm{EL}^{2}}{\mathrm{G}^{2} \mathrm{M}^{5}}\right)$ has dimensions of
  1. angle
  2. acceleration
  3. velocity
  4. time

Solution

Correct option is D angle. $[\mathrm{E}]=\left[\mathrm{ML}^{2} \mathrm{~T}^{-2}\right],[\mathrm{m}]$ $=[\mathrm{M}][\mathrm{I}]=\left[\mathrm{ML}^{2} \mathrm{~T}^{-1}\right],[\mathrm{G}]=\left[\mathrm{M}^{-1} \mathrm{~L}^{3} \mathrm{~T}^{-2}\right]$ $\therefore\left[\frac{\mathrm{El}^{2}}{\mathrm{~m}^{5} \mathrm{G}^{2}}\right]=\frac{\left[\mathrm{ML}^{2} \mathrm{~T}^{-2}\right]\left[\mathrm{M}^{2} \mathrm{~L}^{4} \mathrm{~T}^{-2}\right]}{\left[\mathrm{M}^{5}\right]\left[\mathrm{M}^{-2} \mathrm{~L}^{6} \mathrm{~T}^{-4}\right]}$ $=\left[\mathrm{M}^{0} \mathrm{~L}^{0} \mathrm{~T}^{0}\right]$ As angle has no dimensions, therefore $\frac{\mathrm{El}^{5}}{\mathrm{~m}^{5} \mathrm{G}^{2}}$ has the same dimensions as that of angle. /

Asked in: MHT CET 2020 (13 Oct Shift 1)

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