Electric Potential and Capacitance: Master the Fundamentals with Interactive Quizzes

Question 1

What is the energy stored in a capacitor?

Accepted Answer

1/2 CV^2

Answer

CV^2

Answer

1/4 CV^2

Answer

4 CV^2

Question 2

What is the relationship between the electric field and the electric potential?

Accepted Answer

Electric field is the negative gradient of electric potential.

Answer

Electric potential is the negative gradient of electric field.

Answer

Electric field and electric potential are unrelated.

Answer

Electric field is proportional to electric potential.

Question 3

Which factor does NOT affect the capacitance of a capacitor?

Accepted Answer

Voltage applied to the capacitor

Answer

Area of the plates

Answer

Distance between the plates

Answer

Material between the plates

Question 4

How does the presence of a dielectric material between the plates of a capacitor affect its capacitance? Provide a specific example to illustrate your explanation.

Accepted Answer

The presence of a dielectric material increases capacitance by reducing the electric field strength between the plates.

Answer

The presence of a dielectric material decreases capacitance by increasing the distance between the plates.

Answer

The presence of a dielectric material has no effect on capacitance.

Answer

The presence of a dielectric material decreases capacitance by decreasing the electric field strength between the plates.

Question 5

Define electric potential. What does it represent?

Accepted Answer

Energy required to move a charged particle from infinity to a given point

Answer

Energy stored per unit charge in a capacitor

Answer

Force acting on a charged particle at a given point

Answer

Voltage difference between two points in an electric field

Question 6

In a series circuit containing a capacitor, describe the phase relationship between the voltage across the capacitor and the current.

Accepted Answer

Is 90 degrees out of phase with the current

Answer

Is in phase with the current

Answer

Is 180 degrees out of phase with the current

Answer

Can be any of the above depending on the frequency

Question 7

Provide an example of a practical application that utilizes the energy stored in capacitors.

Accepted Answer

Defibrillators

Answer

Flashlights

Answer

Batteries

Answer

Transistors

Question 8

A capacitor is connected to a battery. Which of the following statements is incorrect?

Accepted Answer

The capacitance of the capacitor is directly proportional to the distance between the plates.

Answer

The potential difference across the capacitor plates is equal to the voltage of the battery.

Answer

The charge stored on the capacitor plates is proportional to the potential difference.

Answer

The energy stored in the capacitor is proportional to the square of the potential difference across it.

Question 9

Which of the following is NOT an application of capacitors?

Accepted Answer

Amplification

Answer

Energy storage

Answer

Filtering

Answer

Tuning circuits

Question 10

What is the equivalent capacitance of two capacitors connected in parallel?

Accepted Answer

The sum of their individual capacitances

Answer

The average of their individual capacitances

Answer

The larger of their individual capacitances

Answer

The smaller of their individual capacitances

Question 11

What is the time constant of a circuit with a resistor of 100 ohms and a capacitor of 100 microfarads?

Accepted Answer

100 milliseconds

Answer

10 milliseconds

Answer

1 second

Answer

10 seconds

Question 12

In an electric field, electric potential is defined as:

Accepted Answer

Work done per unit charge in moving it from one point to another

Answer

Force experienced by a positive charge at that point

Answer

Energy stored per unit charge in a capacitor

Answer

Potential difference between two points in the field

Question 13

A capacitor stores electrical energy primarily in the form of:

Accepted Answer

Electric field between its plates

Answer

Magnetic field around its plates

Answer

Chemical energy within its plates

Answer

Mechanical energy in its spring

Question 14

The capacitance of a capacitor depends primarily on:

Accepted Answer

Geometry and material of its plates, and their separation distance

Answer

Voltage applied across its plates and the current flowing through it

Answer

Frequency of the alternating current applied to it

Answer

Temperature of the surrounding environment

Question 15

The SI unit of capacitance is:

Accepted Answer

Farad (F)

Answer

Coulomb (C)

Answer

Volt (V)

Answer

Ohm (Ω)

Question 16

In a parallel plate capacitor, increasing the distance between the plates will:

Accepted Answer

Decrease capacitance

Answer

Increase capacitance

Answer

Have no effect on capacitance

Answer

Reverse the polarity of the capacitor

Question 17

A capacitor stores 10 μC of charge when connected to a 12 V battery. Calculate the energy stored in the capacitor.

Accepted Answer

120 μJ

Answer

60 μJ

Answer

720 μJ

Answer

1440 μJ

Question 18

In a parallel-plate capacitor, the electric field between the plates is:

Accepted Answer

Uniform and perpendicular to the plates

Answer

Non-uniform and parallel to the plates

Answer

Zero

Answer

Dependent on the distance between the plates

Question 19

Which of the following materials is a good dielectric for a capacitor?

Accepted Answer

Rubber

Answer

Copper

Answer

Salt water

Answer

Aluminum

Question 20

In an RC circuit, the time constant represents:

Accepted Answer

The time it takes for the capacitor to charge to 63% of its maximum voltage

Answer

The time it takes for the capacitor to fully charge

Answer

The time it takes for the capacitor to discharge to 37% of its maximum voltage

Answer

The resistance of the circuit multiplied by the capacitance

Question 21

What is a property of an equipotential surface?

Accepted Answer

Electric potential is constant on the surface

Answer

Electric field is perpendicular to the surface

Answer

Electric field is parallel to the surface

Answer

Electric potential gradient is zero on the surface

Question 22

The electric potential at a point is defined as the amount of work done per unit charge to bring a positive test charge from infinity to that point. What is the SI unit of electric potential?

Accepted Answer

Volt

Answer

Joule

Answer

Coulomb

Answer

Farad

Question 23

A capacitor stores energy in the form of:

Accepted Answer

Electric field

Answer

Magnetic field

Answer

Gravitational field

Answer

Mechanical energy

Question 24

Which of the following is the equation for capacitance of a parallel-plate capacitor?

Accepted Answer

C = ε₀A / d

Answer

C = Q / V

Answer

C = V / Q

Answer

C = ε₀d / A

Question 25

A capacitor has a capacitance of 10 μF. What is the charge stored on the plates when the voltage across the capacitor is 10 V?

Accepted Answer

100 μC

Answer

10 μC

Answer

1 μC

Answer

0.1 μC

Question 26

Which of the following materials is a good dielectric for a capacitor?

Accepted Answer

Rubber

Answer

Copper

Answer

Aluminum

Answer

Salt water

Question 27

Three capacitors (C₁, C₂, C₃) are connected in series. What is their total equivalent capacitance?

Accepted Answer

1 / (1/C₁ + 1/C₂ + 1/C₃)

Answer

C₁ + C₂ + C₃

Answer

C₁ * C₂ * C₃

Answer

(C₁ + C₂) * C₃

Question 28

When selecting a capacitor for a specific application, which key factors should be considered?

Accepted Answer

Capacitance value, voltage rating, and physical constraints

Answer

Capacitance value and voltage rating only

Answer

Voltage rating and physical constraints only

Question 29

In a capacitor, energy is primarily stored as:

Accepted Answer

Electric Field

Answer

Magnetic Field

Answer

Chemical Energy

Answer

Mechanical Energy

Question 30

To maximize a capacitor's energy storage capacity, which material combination is optimal?

Accepted Answer

Thick, conductive plates with a thin dielectric

Answer

Thin, non-conductive plates with a thick dielectric

Answer

Thick, non-conductive plates with a thin dielectric

Answer

Thin, conductive plates with a thick dielectric

Question 31

Which technique is commonly used to measure the capacitance of a capacitor?

Accepted Answer

Capacitance meter

Answer

Wheatstone bridge

Answer

Voltmeter

Answer

Ammeter

Question 32

In an electric field, electric potential is defined as the amount of work done per unit what?

Accepted Answer

Charge

Answer

Mass

Answer

Time

Answer

Energy

Question 33

The primary function of a capacitor is to store:

Accepted Answer

Electric charge

Answer

Magnetic flux

Answer

Thermal energy

Answer

Radio waves

Question 34

The energy stored in a capacitor is given by the formula:

Accepted Answer

1/2 CV^2

Answer

CV

Answer

C^2V

Answer

V^2/C

Question 35

Capacitors can be connected in series or parallel to:

Accepted Answer

Modify capacitance and voltage ratings

Answer

Reduce current flow

Answer

Enhance magnetic fields

Answer

Increase power dissipation

Question 36

The electric field strength within a parallel-plate capacitor is:

Accepted Answer

Uniform and perpendicular to the plates

Answer

Is zero between the plates

Answer

Varies linearly from one plate to the other

Answer

Is non-uniform and parallel to the plates

Question 37

When a dielectric material is inserted between the plates of a parallel-plate capacitor, its capacitance:

Accepted Answer

Increases

Answer

Remains the same

Answer

Decreases

Answer

Becomes negative

Question 38

If the charge on a capacitor is doubled, its potential:

Accepted Answer

Doubles

Answer

Quadruples

Answer

Remains the same

Answer

Halves

Question 39

In an RC circuit, the time constant is determined by:

Accepted Answer

RC

Answer

R^2C

Answer

C/R

Answer

R/C

Question 40

In an electric field, the electric potential at a point is defined as:

Accepted Answer

The amount of work done per unit positive charge in moving it from infinity to the given point

Answer

The charge density at that point

Answer

The force experienced by a unit positive charge at that point

Question 41

Which of the following is NOT a factor that affects the capacitance of a parallel-plate capacitor?

Accepted Answer

Shape of the plates

Answer

Area of the plates

Answer

Distance between the plates

Answer

Permittivity of the dielectric

Question 42

The capacitance of a capacitor is measured in:

Accepted Answer

Farads

Answer

Henries

Answer

Coulombs

Answer

Joules

Question 43

Which of the following materials is commonly used as a dielectric in capacitors?

Accepted Answer

Ceramic

Answer

Aluminum

Answer

Steel

Answer

Copper

Question 44

Capacitors are primarily used in:

Accepted Answer

Electrical circuits

Answer

Mechanical systems

Answer

Thermal systems

Answer

Hydraulic systems

Question 45

Which of the following best describes electric potential?

Accepted Answer

The amount of electrical potential energy per unit charge.

Answer

The force exerted by an electric field on a negative charge.

Answer

The change in electric potential energy over a given distance.

Question 46

Which of the following factors does NOT affect the capacitance of a parallel-plate capacitor?

Accepted Answer

Temperature

Answer

Plate area

Answer

Distance between plates

Answer

Dielectric material

Question 47

Which of the following capacitor configurations has the highest equivalent capacitance?

Accepted Answer

Three capacitors in parallel

Answer

Three capacitors in series

Answer

Two capacitors in parallel and two in series

Answer

Two capacitors in series and two in parallel

Question 48

Which of the following materials is commonly used as a dielectric in capacitors?

Accepted Answer

Ceramic

Answer

Copper

Answer

Aluminum

Question 49

Three capacitors with capacitances of 2 μF, 4 μF, and 6 μF are connected in parallel. What is the equivalent capacitance of this combination?

Accepted Answer

12 μF

Answer

4 μF

Answer

8 μF

Answer

6 μF

Question 50

An electron is accelerated through a potential difference of 100 V. What is the kinetic energy gained by the electron?

Accepted Answer

1.6 x 10^-17 J

Answer

8 x 10^-18 J

Answer

4 x 10^-18 J

Question 51

A capacitor is connected to a battery with an electromotive force (EMF) of 6 V. Once the capacitor is fully charged, what is the potential difference across its plates?

Accepted Answer

6 V

Answer

1 V

Answer

2 V

Answer

3 V