# Electrostatic suspension/Quiz

The image is an artist concept of Gravity Probe B spacecraft in orbit around the Earth. Credit: NASA/MSFC.

Electrostatic suspension is a lecture in the repellor vehicle series.

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## Quiz

1

The equation for the ion current is likely to include which of the following?

 the mass of the electron the number of electrons e to the grain capacitance factor the dust grain radius a 4πr factor

2

True or False, A calculation of energy is not possible unless a mass is involved.

 TRUE FALSE

3

Which of the following is not an electron volt?

 the angular momentum of the planet Mercury around the Sun a unit of energy a quantity that denotes the ability to do work 1.2 PeV a unit dimensioned in mass, distance, and time a unit not based on the Coulomb

4

Which of the following are phenomena associated with electromagnetic cascades?

 spectral and timing properties of astronomical sources very high-energy γ-rays the way from the source to the Earth soft X-rays redshifts ambient radiation fields inside the γ-ray source source stability protons

5

True or False, A unit vector is a direction with a magnitude of one.

 TRUE FALSE

6

Which of the following may not be able to slow down an object entering the heliosphere at 20 km/s?

 gravity electrostatic repulsion the charge on the surface of the Sun a comparable charge on the incoming object electromagnetics strong forces

7

True or False, For the photosphere to have a net negative charge and interstellar electrons to be streaming into the solar system, the sign of the voltage at the Sun is positive.

 TRUE FALSE

8

True or False, When the magnetic poles of the Sun reverse during the solar cycle, there is a short time in which the polar diameter is greater than the equatorial diameter.

 TRUE FALSE

9

Which of the following are associated with electromagnetics?

 angular momentum transfer solar wind protons electrons the baryon neutrino charge neutralization

10

Which of the following are associated with the envelope of the polarization current density?

 emission of electromagnetic radiation from a superluminal charged particle intensity of some components decays as the inverse of the distance from the source non-spherically-decaying sources emission contains very high frequencies not present in the synthesis of the source non-spherically decaying components of the radiation do not violate energy conservation strong electromagnetic fields are compensated by weak fields elsewhere

11

If energy is the impetus behind all motion and activity, which of the following are associated with power?

 a launch location a rate of change of the impetus with time photon density an acceleration of the impetus neutrinos dynamically dominating baryons a rate of change of mass

12

Complete the text:

 Match up the radiation mathematics symbol with the radiation phenomena: thermal neutron capture rate - A change in particle diameter - B power law - C Planck constant - D Boltzmann constant - E electrostatic force - F Jeans length - G ${\displaystyle h}$ . ${\displaystyle \lambda _{J}}$ . ${\displaystyle \varphi _{n}}$ . ${\displaystyle F_{q}}$ . ${\displaystyle ax^{k}}$ . ${\displaystyle k_{B}}$ ${\displaystyle C_{D}}$ .

## Hypotheses

1. Questions linking the various fields overlapping electrostatic suspension make differentiating questions.