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Question 1 of 25
1. Question
1 pointsUnit of Capacitance is:
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Question 2 of 25
2. Question
1 pointsCapacitance value of a capacitor is directly proportional to the distance between the plates:
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Question 3 of 25
3. Question
1 pointsCapacitance value is directly proportional to the length of the plates:
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Question 4 of 25
4. Question
1 pointsIn a dc circuit, fully charged capacitor acts as:
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Question 5 of 25
5. Question
1 pointsCapacitor Charge and Discharge in ___ manner:
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Question 6 of 25
6. Question
1 pointsAir has a dielectric constant of:
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Question 7 of 25
7. Question
1 pointsIn a capacitive circuit, voltage waveform leads current waveform:
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Question 8 of 25
8. Question
1 pointsCapacitors are used for power factor improvement in industrial applications:
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Question 9 of 25
9. Question
1 pointsIn a capacitor energy is stored in dielectric:
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Question 10 of 25
10. Question
1 pointsWhich of the following equation is correct:
 Q = Charge in Coulomb
 C = Capacitance in Farad
 V = Voltage in Volts
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Question 11 of 25
11. Question
1 pointsThe capacitive time constant is the time required for the capacitor to charge (or discharge) to ___ of its fully charged voltage
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Question 12 of 25
12. Question
1 pointsThe attraction of charges in the opposite plates of a capacitor opposes a change in ____ across the capacitor
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Question 13 of 25
13. Question
1 pointsWhich of the following material can be used as Dielectric that is placed between two plates in a Capacitor:
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Question 14 of 25
14. Question
1 pointsThe capacitor will not remain in charged state when a battery supply is removed:
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Question 15 of 25
15. Question
1 pointsIn a Capacitor while Charging, the movement of charges from one plate to another will continue until the charge difference between both the plates is equal to voltage of the supplying battery:
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Question 16 of 25
16. Question
1 points________ is described as the ability of the dielectric to store electrical energy in Capacitor
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Question 17 of 25
17. Question
1 pointsThe capacitance value of a capacitor will not depends on the dielectric constant of the Insulating Material but depends on the area of the conductor plates and distance between the plates
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Question 18 of 25
18. Question
1 pointsFind the capacitance value of a capacitor which can stores 8 C of charge at 4 V:
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Question 19 of 25
19. Question
1 pointsCalculate the charge taken on by a 5F capacitor at 2 volts
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Question 20 of 25
20. Question
1 pointsCalculate the Capacitance value in a circuit having 3 capacitors each of rating 6F in parallel:
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Question 21 of 25
21. Question
1 pointsCalculate the time constant of a 100 μF capacitor in series with a 100 Ohms resistor:
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Question 22 of 25
22. Question
1 pointsResistance in a circuit will cause the delay in the time for charging a capacitor:
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Question 23 of 25
23. Question
1 pointsThe capacitor is considered to be fully charged after a time period of about ___ time constants
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Question 24 of 25
24. Question
1 pointsWhen the supply frequency increases, then the Capacitive Reactance (X_{c }) in a circuit will:
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Question 25 of 25
25. Question
1 pointsPower Factor can be improved by placing which of the following in the circuit
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Capacitance Basic Theory:
Capacitance is a device which opposes the sudden change in the voltage in a circuit. Simplest type of capacitor can be constructed by placing two metal plates which are separated by small distance. The gap between the metal plates is filled with insulating material called dielectric.
For a given capacitor, factors which capacitance value of the capacitor depends are:
 The area of the plates
 The distance between the plates
 The type of dielectric used between the plates
Greater or larger the surface area of the plates, the more will be the capacitance value of the capacitor. Larger the distance between the plates, less will be capacitance value of the capacitor.
Capacitor in DC Circuit:
When a capacitor is charged with battery, electrons from the positive plate (connected to positive terminal of battery) is removed and deposited on the negative plate (connected to negative terminal of battery) of the capacitor. The flow of electrons (current) until equal voltage establish between the positive and negative plates of the capacitor which is equal to battery voltage. When the voltages becomes equal, the capacitor is fully charged and flow of current in the circuit stops. When the dc supply (battery) to the circuit is removed, the charged capacitor will discharge if a closed path is provided and current flows in the circuit.
Thus in dc circuit, capacitor charges until both the plates reaches equal potential. After charging it acts as open circuit.
Dielectric:
Energy stored in the capacitor is in the dielectric and the type of dielectric is important to determine the amount of capacitance of a capacitor. Dielectric materials are assigned with dielectric constants (numbers). Air is assigned as 1 and is taken as reference dielectric.
Capacitance Unit:
The basic unit of capacitor is Farad and its symbol id “F”. A Capacitor has a capacitance of one farad when a charge of one volt across its plate results in movement of one coulomb.
Q = C X V
Where
 Q = Charge in Coulomb
 C = Capacitance in farads
 V = Charging Voltage
Some Important Points Related to Capacitor:
 Capacitor oppose the sudden change in the voltage in a circuit
 Capacitors charge and discharge at an exponential rate
 In a capacitor circuit current leads the voltage by 90^{o}
 Capacitors are used for power factor improvement in industrial applications, to produce phase shift for thyristors (SCR and Traic Circuits), to filter pulsating dc and in RC timing circuits