Question 1

When a capacitor charges and discharges with a varying voltage applied, ______________ current can flow.

Accepted Answer

alternating

Question 2

The symbol for ______________ reactance is X_C.

Accepted Answer

capacitive

Question 3

The base unit for capacitive reactance is the ______________.

Accepted Answer

ohm

Question 4

For a capacitor, the charge and discharge current flows to and from the plates not through the ______________.

Accepted Answer

The answer of For a capacitor, the charge and discharge...

Question 5

A very common application for a capacitor is to block ______________.

Accepted Answer

The answer of A very common application for a capacitor...

Question 6

Capacitive reactance is a measure of a capacitor's ______________ to the flow of alternating current.

Accepted Answer

The answer of Capacitive reactance is a measure of a...

Question 7

In the formula for capacitive reactance, the constant factor 2π is always ______________.

Accepted Answer

The answer of In the formula for capacitive reactance, the...

Question 8

Capacitive reactance is ______________ proportional to frequency.

Accepted Answer

The answer of Capacitive reactance is ______________ proportional to frequency....

Question 9

When analyzing electronic circuits, capacitors are often treated as a ______________ for ac.

Accepted Answer

The answer of When analyzing electronic circuits, capacitors are often...

Question 10

For parallel reactances, the combined reactance is calculated by the ______________ formula.

Accepted Answer

The answer of For parallel reactances, the combined reactance is...

Question 11

The symbol for capacitive reactance is

Accepted Answer

Capacitive reactance is represented by the symbol $X_C$, which is option C.

Question 12

A measure of a capacitor's opposition to the flow of alternating current is

Accepted Answer

Capacitive reactance is the measure of a capacitor's opposition to the flow of alternating current. It is frequency-dependent and inversely proportional to both the frequency of the AC signal and the capacitance.

Question 13

X<sub>C</sub> equals

Accepted Answer

The answer of X_C equals ...

Question 14

In the formula for capacitive reactance, the constant factor 2? is always

Accepted Answer

The constant factor $2\pi$ is approximately equal to 6.28, which is used in the formula for capacitive reactance.

Question 15

How much X_C will there be if the capacitance is 10 ?F and the frequency is 1400 Hz?

Accepted Answer

The reactance of a capacitor (XS) is given by the formula XS = 1 / (2πfC), where f is the frequency in hertz (Hz), C is the capacitance in farads (F), and π is approximately 3.14159. Plugging in the given values (f = 1400 Hz, C = 10 μF = 10 x 10^-6 F), XS = 1 / (2 * 3.14159 * 1400 * 10 x 10^-6) = 1 / (2 * 3.14159 * 1400 * 10^-5) ≈ 11.4 ohms.

Question 16

Which of the following is correct?

Accepted Answer

The capacitive reactance (X_C) is inversely proportional to both the capacitance (C) and the frequency (f), as given by the formula X_C = 1/(2πfC).

Question 17

Because of the inverse relation between X_C and f or C, the graph of X_C versus C is

Accepted Answer

The inverse relationship between X_C and C suggests that as one increases, the other decreases in a nonlinear manner, typically resulting in a hyperbolic curve.

Question 18

When analyzing electronic circuits, capacitors are often treated as

Accepted Answer

Capacitors block direct current (DC) but allow alternating current (AC) to pass through. This is because the capacitor's impedance decreases with increasing frequency. At DC (0 Hz), a capacitor acts as an open circuit, while at high frequencies, it can be considered a short circuit.

Question 19

What is the total capacitive reactance in a series circuit if three capacitors offered 150 ? of reactance each?

Accepted Answer

Capacitive reactance is inversely proportional to capacitance. In a series circuit, the total capacitive reactance is the sum of the individual capacitive reactances. Therefore, the total capacitive reactance in this circuit is 150 ? + 150 ? + 150 ? = 450 ?.

Question 20

For parallel reactances, the combined reactance is calculated by

Accepted Answer

The combined reactance of parallel reactances is calculated using the reciprocal formula, similar to calculating parallel resistances, where the reciprocal of the total reactance is the sum of the reciprocals of the individual reactances.

Quiz 18: Capacitive Reactance