find the total capacitance if two capacitors of 20uf and 5uf are connected in series and if they are connected in parallel in. answer
Answers
Answer:
We know that half the energy supplied by the battery is lost as heat while charging the capacitor it means if a battery supplies the energy E
B
, then the energy store in the capacitor is
2
1
E
B
.
Now, from the question
equivalent capacitance =
C
1
+C
2
C
1
C
2
=
10+20
10×20
=200/30=
3
20
Energy stored in this capacitors =
2
1
CV
2
=
2
1
×
30
20
×(6)
2
=10×12=120
Total charge =CV=
3
20
×6=40μC
Thus potential drop across the capacitor (C
1
) is given by V
1
=
10
40
=4
and potential drop across the capacitor (C
2
) is given by V
2
=
20
40
=2
Energy stored in C
1
=
2
1
×40×4=80
Energy stored in C
2
=
2
1
×40×2=40=E (given)
Thus energy stored in capacitor C
1
=2E
Thus total energy in the capacitors =120=3E
Hence energy supplied by battery =2×3E=6E