Two tiny spheres carrying charges `1.8 muC and 2.8 mu C` are located at 40 cm apart. The potential at the mid-point of the line joining the two charges is

Options

A. `3.8xx10^(4)V`
B. `2.1xx10^(5)V`
C. `4.3xx10^(4)V`
D. `6.3xx10^(5)V`

Answer

B

Explanation

here, `q_1=1.8 muC=1.8xx10^(-6)C , q_2=2.8 muC = 2.8xx10^(-6)C`

Distance between the two spheres = 40 cm = 0.4 cm
For the mid-point `r_1=r_2=0.40/2=0.2 m`
Potential at O, `V=1/(4piepsilon_0)[q_1/r_1+q_2/r_2]=(9xx10^9(1.8+2.8)xx10^(-6))/0.2`
`=2.1xx10^5`V