Question

An electron moving in a electric moving potential field V enters a higher electric potential field V then the change in kinetic energy of the electron is proportional to.

Answer 1

As per Kinetic energy-work theorem(Work energy principle)

$\Delta K_E=W=-\Delta U=(U_2-U_1)$ -----------(A)

From electric potential difference between lower region and higher region is given by,

$V_h-V_l=\frac{-\Delta U}{q}$

$q(V_h-V_l)=-\Delta U$------------(B)

Now putting B in A we get,

$\Delta K_E=q(V_h-V_l)$

$\Delta K_E\alpha (V_h-V_l)$