Physics - W.E.P. Question with Solution | TestHub

As$\mathrm{U}=-\mathrm{\lambda }\left(\mathrm{x}+\mathrm{y}+\mathrm{z}\right)$

At point$\left(\mathrm{1,1},1\right)$potential energy is,

${\mathrm{U}}_1=-\mathrm{\lambda }\left(1+1+1\right)$

${\mathrm{U}}_1=-3\mathrm{\lambda }$

At point$\left(\mathrm{2,3},4\right)$potential energy is,

${\mathrm{U}}_2=-\mathrm{\lambda }\left(2+3+4\right)$

${\mathrm{U}}_2=-9\mathrm{ }\mathrm{\lambda }$

Charge in potential energy,

$\mathrm{\Delta }\mathrm{U}={\mathrm{U}}_2-{\mathrm{U}}_1$

$\mathrm{\Delta }\mathrm{U}=\left(-9\mathrm{\lambda }\right)-\left(-3\mathrm{\lambda }\right)$

$\mathrm{\Delta }\mathrm{U}=-6\mathrm{\lambda }$

$\therefore$Work done$=-\mathrm{\Delta }\mathrm{U}$

$\mathrm{W}=6\mathrm{\lambda }$