Deck 24: Appendix C: Impedance

Question 1

Impedance is ______________.

A) the amount of electrical friction in a wire.
B) a meaningless audio term.
C) a measure of sound insulation.
D) the resistance of a circuit to alternating current, such as an audio signal.

Answer 1

B

Question 2

A bridging load impedance is _______________.

A) slightly higher than the source impedance.
B) much higher than the source impedance.
C) much lower than the source impedance.
D) equal to the source impedance.

Answer 2

D

Question 3

Impedance is measured in __________.

A) amperes.
B) ohms.
C) oersteds.
D) volts.

Answer 3

A

Question 4

Bridging connections result in _____________.

A) the most voltage transferred between components.
B) the most current transferred between components.
C) the least hum and noise.
D) the most reliable connections.

Question 5

Connecting a high-Z source to a low-Z load results in ______________.

A) signal gain or altered resistance.
B) no change in the signal.
C) distortion or altered frequency response.
D) noise or hum.

Question 6

To match a high-impedance electrical guitar to a low-impedance mic input, use _____________.

A) an adapter cable.
B) a resistor in-line with the signal.
C) a guitar amp emulator.
D) a direct box.

Question 7

A low-Z mic can be used with how many feet of cable?

A) no limit
B) hundreds
C) dozens
D) less than 15

Question 8

To connect a phantom-powered mic with an XLR connector to a mixer with a phone-jack input, use __________.

A) a direct box.
B) a phantom power supply and an XLR-to-phone adapter.
C) another mixer.
D) a Y-cable.

Question 9

What happens if you connect two or more signal sources to one input?

A) Nothing; that is normal.
B) Double the signal level.
C) Level loss and distortion.
D) An impedance-matching connection.

Question 10

Microphones and line outputs are usually ___________.

A) Low-Z.
B) High-Z.
C) Medium-Z.
D) matched in impedance.

Question 11

If you wire two 8-ohm speakers in parallel to an amplifier output, the amplifier "sees" ________.

A) 8 ohms.
B) 2 ohms.
C) 4 ohms.
D) 16 ohms.