The potential of a conductor having 40 esu of capacitance is raised by 10 esu. What is the charge on the conductor ? How much charge is to be given to another conductor, having capacitance three times that of the first conductor, to raise its potential three times that of the first one?

Explanation

Charge given to the first conductor,
`Q_1= C_1V_1= 40 xx10 = 400` esu of charge
Capacitance of the second conductor,
`C_2= 3C_1=3xx40 = 120` esu of capacitance
Potential rise of the second conductor,
`V_2 = 3 xx10 = 30` esu of potential
Charge to be given to the second conductor,
`Q_2 = C_2V_2 = 120 xx 30 = 3600` esu of charge.