CAPACITANCE AND CAPACITIVE REACTANCE

Question 1

What is the base unit of measurement for capacitance?

Answer 1

Farad

Question 2

If the distance between the plates of a capacitor is increased, then the amount of capacitance would ______

Answer 2

Decrease

Question 3

A basic capacitor consists of two _____ _____ separated by a ________

Answer 3

Metal plates
Dielectric

Question 4

What is the symbol used to represent capacitance?

Answer 4

C

Question 5

What is a unit of measurement for dielectric strength?

Answer 5

kV/mm

Kilovolts per millimetre

Question 6

True of false

When we define the dielectric strength rating of a capacitor, we are referring to the ability of the dielectric to withstand potential difference

Answer 6

True

Question 7

What is the equation for the stored charge of a capacitor?

Answer 7

Q= C x V

Question 8

What is the symbol used to represent the stored charge of a capacitor?

Answer 8

Q

Question 9

What is the equation used to calculate the time constant of an RC circuit?

Answer 9

TC = C x R

Question 10

How many time constants must elapse for a capacitor to become fully charged?

Answer 10

5

Question 11

What percent charged is a capacitor after one time constant?

Answer 11

63.2%

Question 12

What would happen to the capacitive reactance of a capacitor if the value of the AC voltage is increased?

Answer 12

It would stay the same

Question 13

If the capacitance of a purely capacitive circuit is increased, then the current of that circuit would ________

Answer 13

Increase

Question 14

A capacitor is connected to a AC supply.

When the voltage across the capacitor has reached its maximum positive value, then the current in the circuit would be at _____

Answer 14

Zero

Question 15

The unit of measurement for the opposition to current flow created in an AC circuit by a capacitor is an ___

Answer 15

Ohm

Question 16

What is the unit of measurement for the power produced in a capacitive circuit?

Answer 16

Volt-amperes-reactive

Question 17

Reactive power can also be referred to as __________ power

Answer 17

Quadrature

Question 18

The power produced in a capacitive circuit is called _______ power

Answer 18

Reactive

Question 19

What is an example of a variable capacitor?

Answer 19

A radio tuner

Question 20

What are 4 types of capacitors that are only available in the non-polarized type

Answer 20

Paper
Mica
Ceramic
Oil-filled

Question 21

What are the two classifications of electrolytic capacitors?

Answer 21

Polarized and non-polarized

Question 22

What is the unit of measurement for the storaged charge of a capacitor?

Answer 22

Coulomb

Question 23

If the value of capacitance is increased, then the amount of capacitive reactants will _______

Answer 23

Decrease

Question 24

True or false

The unit of measurement for capacitive reactance is the farad

Answer 24

False

Ohms

Question 25

True or false

The current in a purely capacitive AC circuit leads the volt drop across the capacitor by 90°

Answer 25

True

Question 26

What formula is used to find electric charge? (With current and time)

Answer 26

Q= I x t

Current x time

In coulombs

Question 27

What formula is used to find electric charge? (With capacitance and voltage)

Answer 27

Q= C x V

In coulombs

Question 28

What formula is used to find time constant?

Answer 28

T= R x C

In seconds (1 time constant)

For full charge multiply by 5

Question 29

What formula is used to find capacitive reactance?

Answer 29

Xc= 1 / 2(pi)fC In ohms

f=frequency
C=capacitance

Question 30

What is the formula for power in watts?

Answer 30

PR= I^2 x R

In watts

Question 31

What is the formula for reactive power?

Answer 31

Q= Vx • Ix

Reactive voltage x reactive current

In vars

Question 32

In a capacity circuit does current lead or lag by 90°

Answer 32

Current leads by 90°