Answer
415.2k+ views
Hint: In series combination for capacitors the charge on each capacitor is the same. The total voltage in a series combination for voltage source is the sum of individual voltages. On closing the switch the capacitors begin to charge and then acquire equilibrium state.
Complete step by step answer:
A capacitor is an electrically passive device that is used to store electrical energy.
In the given circuit, the voltage sources are in series. Hence, the equivalent voltage for the circuit will be the sum of the individual voltages.
Hence, ${V_{total}} = {V_1} + {V_2}$ -------🡪 (here, ${V_{total}}$ is the equivalent voltage for the circuit)
For the given circuit, ${V_1},{V_2}$ are 12V and 6V respectively.
Thus, equivalent voltage= ${V_{total}} = 12 + 6 = 18V$-------- 🡪(equation 1)
Also, the capacitors ${C_1}$ and ${C_2}$ are in series, hence, equivalent capacitance of the circuit is given by;
$\dfrac{1}{{{C_{eq}}}} = \dfrac{1}{{{C_1}}} + \dfrac{1}{{{C_2}}}$ -------------🡪 (series combination of capacitors)
And, ${C_1} = 4\mu F$, ${C_2} = 8\mu F$----------🡪 (given)
Hence,
$\Rightarrow \dfrac{1}{{{C_{eq}}}} = \dfrac{1}{4} + \dfrac{1}{8}$ ------- 🡪(substituting the values in the formula)
$ = \dfrac{{8 + 4}}{{32}}$
Thus, ${C_{eq}} = \dfrac{{32}}{{12}}$
$\Rightarrow {C_{eq}} = \dfrac{8}{3}$--------------🡪 (equation 2)
Also, we know that, the charge stored in a capacitor is given by,
$Q = CV$-------------- 🡪(here, C is the capacitance, V is the voltage)
Thus, ${Q_{eq}} = {C_{eq}} \times {V_{total}}$
$\Rightarrow {Q_{eq}} = \dfrac{8}{3} \times 18 = 8 \times 6$
Hence,${Q_{eq}} = 48\mu C$.
Also, the capacitors are in series, so the charge in each capacitor is the same.
Thus, ${Q_{eq}} = {Q_1} = {Q_2}$ ---------- 🡪(property of capacitors in series)
Hence, voltage across ${C_1}$ is ${V_1} = \dfrac{{{Q_1}}}{{{C_1}}}$------- 🡪(here, ${Q_1} = {Q_{eq}}$ and ${C_1} = 4\mu F$)
$\Rightarrow {V_1} = \dfrac{{48}}{4} = 12V$
Similarly for voltage across${C_2}$, ${V_2} = \dfrac{{{Q_2}}}{{{C_2}}}$ --------- 🡪(here, ${Q_2} = {Q_{eq}}$ and ${C_2} = 8\mu F$)
$\Rightarrow {V_2} = \dfrac{{48}}{8} = 6V$
Hence, the two capacitors have the same charge. Therefore, option B is correct.
Note:
In series combination the voltage across individual elements is different but the current is the same, hence, the charge is the same.
In parallel combination, the voltage is the same across all elements but the current is different and so is the charge.
Equivalent capacitance for series =$\dfrac{1}{{{C_{eq}}}} = \dfrac{1}{{{C_1}}} + \dfrac{1}{{{C_2}}} + \dfrac{1}{{{C_3}}} + ............$
Equivalent capacitance for parallel = ${C_{eq}} = {C_1} + {C_2} + {C_3} + ............$
Complete step by step answer:
A capacitor is an electrically passive device that is used to store electrical energy.
In the given circuit, the voltage sources are in series. Hence, the equivalent voltage for the circuit will be the sum of the individual voltages.
Hence, ${V_{total}} = {V_1} + {V_2}$ -------🡪 (here, ${V_{total}}$ is the equivalent voltage for the circuit)
For the given circuit, ${V_1},{V_2}$ are 12V and 6V respectively.
Thus, equivalent voltage= ${V_{total}} = 12 + 6 = 18V$-------- 🡪(equation 1)
Also, the capacitors ${C_1}$ and ${C_2}$ are in series, hence, equivalent capacitance of the circuit is given by;
$\dfrac{1}{{{C_{eq}}}} = \dfrac{1}{{{C_1}}} + \dfrac{1}{{{C_2}}}$ -------------🡪 (series combination of capacitors)
And, ${C_1} = 4\mu F$, ${C_2} = 8\mu F$----------🡪 (given)
Hence,
$\Rightarrow \dfrac{1}{{{C_{eq}}}} = \dfrac{1}{4} + \dfrac{1}{8}$ ------- 🡪(substituting the values in the formula)
$ = \dfrac{{8 + 4}}{{32}}$
Thus, ${C_{eq}} = \dfrac{{32}}{{12}}$
$\Rightarrow {C_{eq}} = \dfrac{8}{3}$--------------🡪 (equation 2)
Also, we know that, the charge stored in a capacitor is given by,
$Q = CV$-------------- 🡪(here, C is the capacitance, V is the voltage)
Thus, ${Q_{eq}} = {C_{eq}} \times {V_{total}}$
$\Rightarrow {Q_{eq}} = \dfrac{8}{3} \times 18 = 8 \times 6$
Hence,${Q_{eq}} = 48\mu C$.
Also, the capacitors are in series, so the charge in each capacitor is the same.
Thus, ${Q_{eq}} = {Q_1} = {Q_2}$ ---------- 🡪(property of capacitors in series)
Hence, voltage across ${C_1}$ is ${V_1} = \dfrac{{{Q_1}}}{{{C_1}}}$------- 🡪(here, ${Q_1} = {Q_{eq}}$ and ${C_1} = 4\mu F$)
$\Rightarrow {V_1} = \dfrac{{48}}{4} = 12V$
Similarly for voltage across${C_2}$, ${V_2} = \dfrac{{{Q_2}}}{{{C_2}}}$ --------- 🡪(here, ${Q_2} = {Q_{eq}}$ and ${C_2} = 8\mu F$)
$\Rightarrow {V_2} = \dfrac{{48}}{8} = 6V$
Hence, the two capacitors have the same charge. Therefore, option B is correct.
Note:
In series combination the voltage across individual elements is different but the current is the same, hence, the charge is the same.
In parallel combination, the voltage is the same across all elements but the current is different and so is the charge.
Equivalent capacitance for series =$\dfrac{1}{{{C_{eq}}}} = \dfrac{1}{{{C_1}}} + \dfrac{1}{{{C_2}}} + \dfrac{1}{{{C_3}}} + ............$
Equivalent capacitance for parallel = ${C_{eq}} = {C_1} + {C_2} + {C_3} + ............$
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why Are Noble Gases NonReactive class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
At which age domestication of animals started A Neolithic class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write a letter to the principal requesting him to grant class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)