An air capacitor is charged to a potential of 150 V and then the charging battery is disconnected. If the space between the plates is then completely filled with a material of dielectric constant 10 , then the potential between the plates will become

Options

A. 5 V
B. 10 V
C. 15 V
D. 20 V

Answer

C

Explanation

Q remains constant,
`therefore Q=C_(1)V_(2)=C_(2)V_(2)`
`(C_(2))/(C_(1))=`10 (as the dielectric is introduced)
`therefore (V_(2))/(V_(1))=(C_(1))/(C_(2))=(1)/(10)" "therefore V_(2)=15V`