A body of capacity $4\,\mu \,F$ is charged to $80\,V$ and another body of capacity $6\,\mu \,F$ is charged to $30\,V$. When they are connected the energy lost by $4\,\mu \,F$ capacitor is.......$mJ$
  • A$7.8$
  • B$4.6$
  • C$3.2$
  • D$2.5$
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