Q.

Electric potential at a point 'P' due to a point charge of 5×10-9 C is 50 V. The distance of 'P' from the point charge is

(Assume, 14πε0=9×10-9 Nm2C-2)     [2023]

1 3 cm  
2 90 cm  
3 9 cm  
4 0.9 cm  

Ans.

(2)

VP=KQr

50=9×109×5×10-9r

r=4550=910=0.9 m=90 cm