In Millikan’s oil drop experiment, an oil drop of mass $16 \times {10^{ - 6}}kg$ is balanced by an electric field of ${10^6}V/m.$ The charge in coulomb on the drop, assuming $g = 10\,m/{s^2}$ is
$6.2 \times {10^{ - 11}}$
$16 \times {10^{ - 9}}$
$16 \times {10^{ - 11}}$
$16 \times {10^{ - 13}}$
Answer the following questions:
$(a)$ guarks inside protons and neutrons are thought to carry fractional charges $[(+2 / 3) e ; (-1 / 3) e] .$ Why do they not show up in Millikan's oil-drop experiment?
$(b)$ What is so special about the combination $e / m ?$ Why do we not simply talk of $e$ and $m$ separately?
$(c)$ Why should gases be insulators at ordinary pressures and start conducting at very low pressures?
$(d)$ Every metal has a definite work function. Why do all photoelectrons not come out with the same energy if incident radiation is monochromatic? Why is there an energy distribution of photoelectrons?
$(e)$ The energy and momentum of an electron are related to the frequency and wavelength of the assoctated matter wave by the relations:
$E=h v, p=\frac{h}{\lambda}$
But while the value of $\lambda$ is physically significant, the value of $v$ (and therefore, the value of the phase speed $v \lambda$ ) has no physical significance. Why?
The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally by
Electron volt is a unit of
An electron is moving with constant velocity along $x - $ axis. If a uniform electric field is applied along $y - $ axis, then its path in the $x - y$ plane will be
The current conduction in a discharged tube is due to