An oxide coated filament is useful in vacuum tubes because essentially
It has high melting point
It can withstand high temperatures
It has good machanical strength
It can emit electrons at relatively lower temperatures
Write name of universal and fundamental particle of matter.
Who invented $X-$ rays?
In Bainbridge mass spectrograph a potential difference of $1000 V$ is applied between two plates distant $1$ cm apart and magnetic field in $B = 1T$. The velocity of undeflected positive ions in m/s from the velocity selector is
An electron is moving in electric field and magnetic field it will gain energy from
While doing his experiment, Millikan one day observed the following charges on a single drop
$(i)$ $6.563 \times {10^{ - 19}}C$ $ (ii)$ $8.204 \times {10^{ - 19}}C$
$(iii)$ $11.50 \times {10^{ - 19}}C$ $ (iv)$ $13.13 \times {10^{ - 19}}C$
$(v)$ $16.48 \times {10^{ - 19}}C$ $ (vi)$ $18.09 \times {10^{ - 19}}C$
From this data the value of the elementary charge $(e)$ was found to be