Q.

The distance between charges +q and −q is 2λ and between +2q and −2q is 4λ. The electrostatic potential at point P at a distance r from center O is -α[qlr2]×109V, where the value of α is _______ . (Use 14πε0=9×109 Nm2C-2)              [2024]


Ans.

(27)

V=KPnet·rr3=9×109(6q)r2cos(120°)

=-(27)(qr2)×109 Nm2C-2

α=27