Question

HELP PLZ!
3 capacitors of 20,10,15 uf respectively are connected on series across the 100v supply. find the voltage a cross the 10uf capacitors.

Answer 1

Do you know the formula of net capacitance in series ??

Answer 2

1/ct = 1/c1+1/c2+1/c3 or by reciprocal ct= c1xc2/c1+c2 ?

Answer 3

Great! Then you can find the net charge by Q = CV

As the charge on each capacitor will be same (why? ) you can find the voltage across any one of the capacitors using the same formula (Q = CV)

Answer 4

i dont get it ... will u show me how?

Answer 5

To find net charge (Q) substitute -
C = net capacitance of series combination
V = Voltage
in the formula Q = CV

Then, to find the the voltage across any capacitor (V') substitute -
Q = net charge
C' = capacitance of the concerned capacitor
in the formula Q = C' * V'

Answer 6

so 1st we need to get the value of C=1/20uf +1/10uf + 1/15uf ?

Answer 7

Yea..
LHS would be 1/C

Answer 8

so uf does have value?

Answer 9

uf is a unit.

A personal advice - "Before solving a question, convert all units to SI units and then forget them. Finally place the corresponding SI unit in the answer."