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# Test: Combination Of Capacitors

## 10 Questions MCQ Test Physics Class 12 | Test: Combination Of Capacitors

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This mock test of Test: Combination Of Capacitors for JEE helps you for every JEE entrance exam. This contains 10 Multiple Choice Questions for JEE Test: Combination Of Capacitors (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Combination Of Capacitors quiz give you a good mix of easy questions and tough questions. JEE students definitely take this Test: Combination Of Capacitors exercise for a better result in the exam. You can find other Test: Combination Of Capacitors extra questions, long questions & short questions for JEE on EduRev as well by searching above.
QUESTION: 1

### Here is a combination of three identical capacitors. If resultant capacitance is 1 μƒ, calculate capacitance of each capacitor.

Solution:

Combination of Capacitors in Series
C(effective) = C/3 = 1

QUESTION: 2

Solution:

Definition

QUESTION: 3

### If two spheres of different radii have equal charge, then the potential will be

Solution:

When equal charges are given to two spheres of different radii, the potential will be more or the smaller sphere as per the equation, Potential = Charge / Radius.
Since potential is inversely proportional to radius, the smaller radius will have higher potential and vice versa.

QUESTION: 4

The capacitor preferred for high-frequency circuit is

Solution:

Mica capacitor. Mica capacitors have low resistive and inductive components associated with it. Hence, they have high Q factor and because of high Q factor their characteristics are mostly frequency independent, which allows this capacitor to work at high frequency.

QUESTION: 5

Three different capacitors are connected in series, then:

Solution:

C = Q/V
series connection splits the battery potential, hence....
V = V1 + V2
V1 = Q/C1 & V2 = Q/C2
Therefore, both have equal charge

QUESTION: 6

Calculate the equivalent capacitance for the following combination between points A and B

Solution:

4μf and 6μf are in series (right side of AB) so 6x(4/6)+4=24/10μf
And now 5 μf and the resulting of above two are in parallel (as on different sides of AB) so 5+(24/10) =50+(24/10)=74/10=37/5μf

QUESTION: 7

There are three capacitors with equal capacitance. In series combination, they have a net capacitance of Cand in parallel combination, a net capacitance of C2.What will be the value of C1 C2?​

Solution:

For series combination,
1/C1=(1/C)+(1/C)+(1/C) [ Since all capacitors have equal capacitances]=3/C Or
C1=C/3−−−(i)
For parallel combination,
C2=C+C+C=3C−−−(ii)
Now,C1/C2=(C/3)/3C=(C/3)×(1/3C)=1/9

QUESTION: 8

Two capacitors of 20 μƒ and 30 μƒ are connected in series to a battery of 40V. Calculate charge on each capacitor.​

Solution:

C1= 20×10µf

and C2= 30×10µf

in series Ceq = C1C2/(C1+C2)

Ceq = 20×10^(-6)×30×10^(-6)/20×10^(-6)+30^×10(-6)

Ceq= 12×10^(-6)f

As we know that Q = CV

Putting the values of C and V= 40V, we get

Q = (12 * 10^-6) * 40

= 480µC

QUESTION: 9

Two capacitors of equal capacity are first connected in parallel and then in series. The ratio of the total capacities in the two cases will be

Solution:

Third capacitor is short-circuited as its both ends are connected to B. Equivalent circuit is
Ceq=C+C=2C

QUESTION: 10

When two capacitors C1 and C2 are connected in series and parallel, their equivalent capacitances comes out to be 3μƒ and 16μƒ respectively. Calculate values of C1 and C2.

Solution:

Let Cp be the equivalent capacitance of parallel
Cp=C1+C2
16= C1+C2……..(1)
Let Cs be the equivalent of capacitance in series
1/Cs=(1/C1) + (1/C2)
Or, Cs=C1C2/C1+C2
Or,3=C1C2/16
Or,C2C1=48
C2=48/C1……..(ii)
16=C1+48/C1
(C12-16C1+48)=0
(C1-4)(C1-12)=0
C1=4 ; C1=12
If,
C1=4
C2=12
If,
C2=4
C1=12
So, the answer is, Either 12μf or4μf