Why is a vacuum needed in a vacuum tube?
(N/A) vacuum is required in a vacuum tube to prevent the collision of electrons with air molecules. If air were present,the electrons emitted from the cathode would collide with gas molecules,causing ionization and scattering. This would lead to a decrease in the electron current and could cause electrical discharge or arcing,which would damage the tube and prevent it from functioning as a controlled electronic device.
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The mutual characteristic curves of a triode are as shown in the figure. The cut-off voltage for the triode is.....$V$.
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View SolutionIn the mutual characteristic curve of a triode,which point represents the cut-off voltage?
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View SolutionThe plate current $i_p$ in a triode valve is given by $i_p = K(V_p + \mu V_g)^{3/2}$,where $i_p$ is in $mA$ and $V_p$ and $V_g$ are in $V$. If $r_p = 10^4 \, \Omega$ and $g_m = 5 \times 10^{-3} \, \text{mho}$,then for $i_p = 8 \, mA$ and $V_p = 300 \, V$,what are the values of $K$ and the grid cut-off voltage?
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View SolutionThe amplification factor of a triode is $50$. If the grid potential is decreased by $0.20\, V$,what increase in plate potential will keep the plate current unchanged?
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