Question

if Planck's constant h taken into a new systme of units in which new unit of mass is 10 g, new unit of length is 5 m, new unit of time is 100 s, then the value of planck's constant in new systme is $\left(Givenh=6.6x{10}^{-34}js\right)$

• A. 6.6 $x{10}^{-34}newunit$
• B. 2.64 $x{10}^{-31}newunit$
• C. 26.4 $x{10}^{-31}newunit$
• D. 26.4 $x{10}^{-33}newunit$

Answer 1

The correct option is B 2.64 $x{10}^{-31}newunit$

Given :

Planck's constant , h = 6.6 ×${10}^{-34}Js$

According to new system of units,

$\Rightarrow h=6.6\times {10}^{-34}Kg{m}^2{s}^{-2}s$

$\Rightarrow h=6.6\times {10}^{-34}\times 1000g\times 1m^2\times 1s^{-1}$

$\Rightarrow h=6.6\times {10}^{-34}\times (100\times 10g)\left(\frac{5m\times 5m}{5\times 5}\right)\times (\frac{1}{100s}\times 100)$

$\Rightarrow h=\frac{6.6\times {10}^{-34}\times 100\times 100}{5\times 5}newunit$

$\Rightarrow h=0.264\times {10}^{-30}newunit$

$\Rightarrow h=2.64\times {10}^{-31}newunit$

Hence , the correct option is B