PH 115 Lab 1: Electric Fields - Theory Questions

The breakdown voltage of a gas depends on its

a) partial pressure

b) density

c) temperature

d) all of these

d. all of these

Inductive charging is due to

a) size of the electron

b) Coulomb force

c) transfer of charges from one medium to another

d) none of these

b. Coulomb Force

The charges on a randomly-shaped conductor always reside

a) at its center

b) depends on the material

c) at the surface

c. at the surface

The electron is less massive than the proton

a) true

b) false

a. True

The neutron is much less massive than the proton

a) true

b) false

b. False

An electrostatic luminous spark is a result of

a) electron attraction

b) the photons produced by the electric field

c) collisions between ions or electrons and air molecules

d) none of these

c. Collisions between ions or electrons and air molecules

A Faraday cage can be constructed from

a) a semi-conductor

b) an insulator

c) a non-conductor

d) none of these

d. none of these

Inside a Faraday cage, the electric field is

a) can have any value

b) zero

b. zero

A photon has

a) negative charge

b) depends on the type of photon

c) positive charge

d) no charge

d. no charge

The typical radius of an atom is closer to

a) 10^(-3) m

b) 10^(-15) m

c) 10^(-1) m

b. 10^(-15) m

At any given time, there are electrons in the air that we breathe. This statement is

a) true

b) false

a. true

When accelerated electrons collide with air molecules one of the likely "byproducts" is

a) another molecule

b) there can be no collisions between electrons and molecules

c) a photon

c. a photon

The inductive charging (i.e., the reason we used the smaller dome in the lab) acquires the opposite charge than the main Van de Graaf (VDG) dome because of

a) the negative charge of the electron

b) the VDG using AC current

c) the repelling forces between electrons

d) none of these

c. the repelling forces between electrons

The charges on the VDG reside

a) depends on the dimensions of the VDG

b) on the surface

c) at the center

b. on the surface

The sound from the electrostatic luminous spark we observed in the lab is a result of

a) electron production from excited atoms

b) photons production from excited atoms

c) electron reduction from excited atoms

d) none of these

d. None of these

The charges generated by the VDG are because of

a) Coulomb forces

b) electrical forces

c) frictional forces

d) none of these apply

c. frictional forces

At its natural state, air is

a) an electrical insulator

b) an electrical conductor

a. an electrical insulator

One argues that because the proton is much larger in mass than the electron, it creates a much stronger electric field at the same distance than the electron does. This statement is

a) true

b) false

c) it depends on the proton or electron

b. false

A student argues that the light produced during the VDG spark is due to the thermal expansion of the surrounding air. This statement is

a) true

b) false

b. false

The size of the VDG dome determines

a) the electric potential magnitude on the surface of the sphere

b) how long the sparks can reach

c) how much charge is stored

d) all of these

d. all of these

The electric field at the center of the VDG dome is

a) minimum but non-zero

b) zero

c) maximum

b. zero