Combination of Capacitors - NEET Physics Questions
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Combination of Capacitors

Question 1: moderate

Total capacity of the system of capacitors shown in the following figure between the points A and B is:

1. 1 μF
2. 2 μF
3. 3 μF
4. 4 μF
View Answer

Combination of Capacitors simple questions

The Circled capacitors are in Series so , Their equivalent capacitance is 1 μF . Then it is in parallel with 1 μF capacitor. The circuit will keep on reducing.

Question 2: moderate

The resultant capcitance between A and B in the figure is :

1. 1 μF
2. 10 μF
3. 50 μF
4. 1.5
View Answer

Combination of Capacitors question

For Such Question start solving from the farthest point. The circuit will keep on reducing.

 

Question 3: moderate

Consider the figure, equivalent capacitance between A and B is

1. C
2. 4C/5
3. 5C/4
4. 2C/3
View Answer

Capacitors circled in the diagram are short circuited so, they can be removed from the circuit.Combination of Capacitors

 

Question 4: moderate

Minimum number of 8 μF and 250 V capacitors used to make a combination of 16 μF and 1000 V are:

1. 32
2. 16
3. 8
4. 4
View Answer

To solve this, we determine the combination of capacitors required to achieve the desired capacitance and voltage.


Given:

  • Individual capacitor:
    C=8μFC = 8 \, \mu\text{F}
     

    , Vmax=250VV_{\text{max}} = 250 \, \text{V} 

  • Desired combination:
    Creq=16μFC_{\text{req}} = 16 \, \mu\text{F}
     

    , Vreq=1000VV_{\text{req}} = 1000 \, \text{V} 


Step 1: Voltage requirement

To achieve

Vreq=1000VV_{\text{req}} = 1000 \, \text{V}

, multiple capacitors must be connected in series because the voltage across a series combination adds up. The number of capacitors required in series is:

 

n=VreqVmax=1000250=4n = \frac{V_{\text{req}}}{V_{\text{max}}} = \frac{1000}{250} = 4

 

Thus, 4 capacitors in series are required to handle 1000 V.


Step 2: Capacitance in series

The effective capacitance of

nn

capacitors in series is given by:

 

Cseries=Cn=84=2μFC_{\text{series}} = \frac{C}{n} = \frac{8}{4} = 2 \, \mu\text{F}

 

So, a series of 4 capacitors provides

Cseries=2μFC_{\text{series}} = 2 \, \mu\text{F}

.


Step 3: Capacitance requirement

To achieve

Creq=16μFC_{\text{req}} = 16 \, \mu\text{F}

, multiple such series groups must be connected in parallel because capacitance in parallel adds up. The number of such series groups required is:

 

m=CreqCseries=162=8m = \frac{C_{\text{req}}}{C_{\text{series}}} = \frac{16}{2} = 8

 

Thus, 8 series groups are required.


Step 4: Total capacitors

Each series group contains 4 capacitors, and there are 8 such groups. Therefore, the total number of capacitors is:

 

Total capacitors=nm=48=32\text{Total capacitors} = n \cdot m = 4 \cdot 8 = 32

 


Final Answer:

The minimum number of capacitors required is:

 

32\boxed{32}

 

Question 5: moderate

In the given figure, find the charge flowing through section AB when switch S is closed:

 

1. \[C_{0}E/12\]
2. \[C_{0}E/4\]
3. \[C_{0}E/3\]
4. none of these
View Answer

When Switch is open Ceq= C/4 Charge given by the Battery is CE/4.

When Switch is open Ceq= C/3 Charge given by the Battery is CE/3.

Extra Charge flowing through the circuit it = \( \frac{CE}{3}-\frac{CE}{4}= \frac{CE}{12}\)

 

Question 6: moderate

The equivalent capacitance between points M and N is:

1. \[\frac{10}{11}C_{0}\]
2. \[2C_{0}\]
3. \[C_{0}\]
4. none of these
View Answer

Combination of Capacitors

Circircled ones are in parallel

Question 7: moderate

Seven capacitors, each of capacitance 2 μF, are to be combined to obtain a capacitance of 10/11 μF. Which of the following combinations is possible?

1. 2 in parallel, 5 in series
2. 3 in parallel, 4 in series
3. 4 in parallel, 3 in series
4. 5 in parallel, 2 in series
View Answer

We need to check each option separately. We 5 capacitors are connected  in parallel, 2 capacitors are connected in series.

Ceq= (5C×C/2)/ (5C+C/2)= 5C/11 = 5×2/11 = 10/11 μF.

Question 8: moderate

In the circuit shown, the effective capacitance between points X and Y is:

1. 3.33 μF
2. 1 μF
3. 0.44 μF
4. none of these
View Answer

In the Upper arm 6 μF and 3 μF capacitors are in series , so equivalent capacitance is 2μF. The 3μF capacitor ( circled one) can be removed as it is part of balanced wheat stone bridge.

Question 9: moderate

Calculate the charge on the second capacitor before and after switch in the circuit is closed :

1. CE/2, CE
2. 0, 0
3. 0, CE
4. CE, 0
View Answer

When Switch is Open Equivalent Capacitance is Ceq=C/2

So, Charge on Both the capacitors in CE/2.

When Switch is Closed 1st Capacitor is short circuited .Now  Equivalent Capacitance is Ceq=C.

So, Charge on  the capacitors in CE.