# Homework Help: Measurement of Electric Dipole Moment in hydrogen gas between parallel plate capacito

1. Sep 20, 2009

### iLIKEstuff

1. The problem statement, all variables and given/known data

Part A)
Assume you have a capacitor with H-atom gas with a separation of the plates of $${10}^{-4}$$meter and a voltage of 20 volts across the capacitor. Calculate the distance "d" (the displacement of the charges in the atom), where the induced dipole of the hydrogen atom is $$\mu = {e}^{-} d$$

Part B)

Apparently people have measured this dipole, and therefore are capable of estimating this
distance “d”. Considering the size of “d” that you calculated, explain how it is possible to
“observe” (through the measurement of $$\mu$$) the size of “d”.

2. Relevant equations

3. The attempt at a solution

For Part A) I calculated $$d=\frac{\alpha \cdot \frac{V}{dist}}{q_e}=2.059 \cdot {10}^{-17} meters$$

where
$$\alpha = \text{polarizability} = 1.649 \cdot {10}^{-41}$$
$$V= 20 volts$$
$$dist= {10}^{-4} meters$$
$$q_e= 1.602 \cdot {10}^{-19} coulombs$$

What I don't know is Part B) how do people measure such a small value and estimate the distance??

Thanks for the help.