Capacitance

Question 1

The safest way to discharge a capacitor is with two clip leads attached to a ______ resistor.

a. low-value, low-wattage
b. low-value, high-wattage
c. high-value, low-wattage
d. high-value, high-wattage

Answer 1

b. low-value, high-wattage

Question 2

In a capacitive circuit, the voltage and current are ______ out of phase.

a. 90°
b. 135°
c. 180°
d. 270°

Answer 2

a. 90°

Question 3

Capacitance is measured in ______.

a. coulombs
b. farads
c. henrys
d. ohms

Answer 3

b. farads

Question 4

Capacitance varies “directly” with the ______.

a. distance between plates
b. magnetic strength
c. plate area
d. thickness of dielectric

Answer 4

c. plate area

Question 5

A capacitor label reads 40µf, 60VDC, 10%, what is its “capacitance”?

a. 40 µf
b. 60vdc
c. 10%
d. 20 amps

Answer 5

a. 40 µf

Question 6

A “paper capacitor” is type of ______ capacitor.

a. electrolytic
b. ceramic
c. fixed
d. variable

Answer 6

c. fixed

Question 7

A capacitor with a label that reads only “152” indicates it has a “capacitance” value of ____.

a. 8pF
b. 15.2 pF
c. 152 pF
d. 1500 pF

Answer 7

d. 1500 pF

Question 8

What is the dielectric value of air?

a. 0
b. 1
c. 3
d. 5

Answer 8

b. 1

Question 9

Which type of capacitor has a dielectric composed of a very thin coating of oxide between the two plates?

a. Electrolytic capacitor
b. Fixed capacitor
c. Variable capacitor
d. Tantalum capacitor

Answer 9

a. Electrolytic capacitor

Question 10

If a circuit has a resistance of 1 megohm (1 million ohms), a capacitance of 2µF (0.000002 farada), what is its “time constant” (Tau)?

a. 0.2 seconds
b. 2 seconds
c. 200 seconds
d. 20,000 seconds

Answer 10

b. 2 seconds