Capacitance: Definition, Properties, and Applications in Physics

Question 1

What happens to the charge stored on a capacitor when the battery connected to it is disconnected?

Accepted Answer

It remains the same

Answer

It increases

Answer

It decreases

Answer

It reverses polarity

Question 2

When two capacitors are connected in parallel, what is their combined capacitance?

Accepted Answer

The sum of their individual capacitances

Answer

The difference of their individual capacitances

Answer

The product of their individual capacitances

Answer

The quotient of their individual capacitances

Question 3

What is the function of a resistor connected in series with a capacitor in a charging circuit?

Accepted Answer

To limit the charging current

Answer

To increase the charging current

Answer

To store energy

Answer

To discharge the capacitor

Question 4

Which type of graph accurately represents the relationship between voltage and charge in a capacitor?

Accepted Answer

Linear

Answer

Parabolic

Answer

Hyperbolic

Answer

Exponential

Question 5

Define energy density in the context of capacitors.

Accepted Answer

Energy stored per unit volume

Answer

Energy stored per unit capacitance

Answer

Energy stored per unit surface area

Answer

Energy stored per unit potential difference

Question 6

The energy stored in a capacitor is:

Accepted Answer

Both (A) and (C)

Answer

Equal to the square of the potential difference

Answer

Proportional to the capacitance

Answer

Proportional to the charge stored

Question 7

When a capacitor is connected to a voltage source through a switch, it will:

Accepted Answer

Charge exponentially

Answer

Discharge exponentially

Answer

Charge linearly

Answer

Discharge linearly

Question 8

How does increasing the dielectric constant of a capacitor impact its capacitance?

Accepted Answer

Capacitance increases

Answer

Capacitance decreases

Answer

Capacitance remains unchanged

Answer

Voltage rating increases

Question 9

In an AC circuit, a capacitor is connected in parallel with a resistor. What is the phase difference between the capacitor's voltage and the circuit's current?

Accepted Answer

90°

Answer

0°

Answer

180°

Answer

270°

Question 10

What is the primary function of a filter capacitor in a power supply system?

Accepted Answer

Smoothing voltage fluctuations

Answer

Storing energy for sudden load demands

Answer

Protecting the circuit from short circuits

Answer

Increasing the output voltage

Question 11

In a circuit containing a resistor and a capacitor connected in series, what is the term for the product of resistance and capacitance?

Accepted Answer

RC

Answer

R/C

Answer

C/R

Answer

1/RC

Question 12

A capacitor is discharged through a resistor. Which graph accurately represents the decay of voltage across the capacitor?

Accepted Answer

Exponential decay

Answer

Linear decay

Answer

Parabolic decay

Answer

Sinusoidal decay

Question 13

What does NOT affect the capacitance of a parallel plate capacitor?

Accepted Answer

Voltage applied to the capacitor

Answer

Plate surface area

Answer

Distance between plates

Answer

Material between the plates

Question 14

When a capacitor of capacitance C is connected in parallel with another capacitor of capacitance 2C, the equivalent capacitance of the combination is:

Accepted Answer

2C

Answer

C

Answer

3C

Answer

4C

Question 15

How does the insertion of a dielectric material between the plates of a capacitor affect its capacitance?

Accepted Answer

Increases capacitance

Answer

Decreases capacitance

Answer

No change in capacitance

Answer

Depends on the dielectric material

Question 16

What happens to the stored energy when the plates of a charged capacitor are connected together?

Accepted Answer

Dissipated as heat

Answer

Converted to mechanical energy

Answer

Lost as electromagnetic radiation

Answer

Remains stored in the capacitor

Question 17

Which of the following is the universally accepted unit of capacitance?

Accepted Answer

Farad

Answer

Volt

Answer

Coulomb

Answer

Henry

Question 18

Identify the material that exhibits good dielectric properties.

Accepted Answer

Rubber

Answer

Metal

Answer

Salt water

Answer

Graphite

Question 19

When a capacitor discharges through a resistor, describe the shape of the graph representing voltage across the capacitor plotted against time.

Accepted Answer

Exponential decay

Answer

Linear decay

Answer

Periodic

Answer

Logarithmic

Question 20

In an alternating current (AC) circuit, what is the phase relationship between voltage across a capacitor and current through it?

Accepted Answer

Out of phase by 90 degrees

Answer

In phase

Answer

Out of phase by 180 degrees

Answer

Random

Question 21

What is the primary function of a capacitor in an electrical circuit?

Accepted Answer

Stores electrical charge

Answer

Resists the flow of electric current

Answer

Generates an electric field

Answer

Converts electrical energy into mechanical energy

Question 22

Which type of material is commonly utilized as a dielectric in capacitors?

Accepted Answer

Insulator

Answer

Metal

Answer

Conductor

Answer

Semiconductor

Question 23

What type of energy can be stored in a capacitor?

Accepted Answer

Electrical energy

Answer

Mechanical energy

Answer

Chemical energy

Answer

Thermal energy

Question 24

What is the term for the time it takes for the voltage across a capacitor in an RC circuit to reach 63% of its maximum value?

Accepted Answer

Time constant

Answer

Half-life

Answer

Rise time

Answer

Fall time

Question 25

Which application utilizes the energy stored in capacitors?

Accepted Answer

Camera flash

Answer

Car battery

Answer

Solar cell

Answer

Wind turbine

Question 26

Which factor does NOT influence the capacitance of a capacitor?

Accepted Answer

Humidity

Answer

Area of plates

Answer

Distance between plates

Answer

Material of dielectric

Question 27

The SI unit of capacitance is the:

Accepted Answer

Farad

Answer

Coulomb

Answer

Volt

Answer

Henry

Question 28

Capacitors have a wide range of applications. Which of the following is NOT an application of capacitors?

Accepted Answer

Generating power

Answer

Energy storage

Answer

Filtering

Answer

Timing circuits

Question 29

The time constant of a circuit containing a capacitor and a resistor is:

Accepted Answer

Capacitance divided by resistance

Answer

Resistance divided by capacitance

Answer

Capacitance multiplied by resistance

Answer

Resistance multiplied by capacitance

Question 30

When a capacitor is connected to an AC voltage source, the phase difference between the voltage across the capacitor and the current through it is:

Accepted Answer

90 degrees

Answer

0 degrees

Answer

180 degrees

Answer

270 degrees

Question 31

Which type of capacitor is polarized?

Accepted Answer

Electrolytic

Answer

Ceramic

Answer

Film

Answer

Tantalum

Question 32

A capacitor is used in a camera flash to store energy. What is the primary function of the capacitor in this application?

Accepted Answer

Store charge and release it quickly

Answer

Provide a high voltage for the flash

Answer

Limit the current flow

Answer

Filter out noise

Question 33

In a voltage regulator circuit, what is the main purpose of a capacitor?

Accepted Answer

To stabilize the voltage across the load, compensating for variations in the input voltage.

Answer

To act as a temporary storage for excess charge in the circuit.

Answer

To remove alternating current (AC) components from the input voltage.

Answer

To prevent potential short circuits within the circuit.

Question 34

Which of the following is the SI unit of capacitance?

Accepted Answer

Farad (F)

Answer

Volt (V)

Answer

Henry (H)

Answer

Coulomb (C)

Question 35

Which of the following factors does capacitance NOT depend on?

Accepted Answer

Shape of the plates

Answer

Plate area

Answer

Permittivity of the material

Answer

Distance between plates

Question 36

A capacitor is connected to a battery and allowed to fully charge. What is the energy stored in the capacitor?

Accepted Answer

1/2 CV²

Answer

CV

Answer

1/4 CV²

Answer

2CV²

Question 37

Two capacitors with capacitances C1 and C2 are connected in parallel. What is the equivalent capacitance of the combination?

Accepted Answer

C1 + C2

Answer

C1 - C2

Answer

C1 / C2

Answer

C1 * C2

Question 38

Two capacitors with capacitances C1 and C2 are connected in series. What is the equivalent capacitance of the combination?

Accepted Answer

1 / (1 / C1 + 1 / C2)

Answer

C1 * C2

Answer

C1 - C2

Answer

C1 + C2

Question 39

A capacitor is charged and then isolated. What happens to the energy stored in the capacitor?

Accepted Answer

It remains constant

Answer

It decreases

Answer

It increases

Answer

It becomes zero

Question 40

Which type of material is a common dielectric used in capacitors?

Accepted Answer

Ceramic

Answer

Semiconductor

Answer

Metal

Answer

Conductor

Question 41

Which of the following materials is NOT suitable for use as a dielectric in a capacitor?

Accepted Answer

Copper

Answer

Paper

Answer

Ceramic

Answer

Plastic

Question 42

What is the effect of connecting two capacitors in parallel?

Accepted Answer

Increased capacitance

Answer

Unchanged capacitance

Answer

Reversed polarity

Answer

Decreased capacitance

Question 43

What is the relationship between capacitance and the distance between capacitor plates?

Accepted Answer

Inversely proportional

Answer

Directly proportional

Answer

Logarithmically proportional

Answer

No relationship

Question 44

What is the purpose of a bypass capacitor in an electrical circuit?

Accepted Answer

To provide a low-resistance path to ground for high-frequency signals

Answer

To block direct current

Answer

To store energy for long periods