Why are digital signals more resistant to noise than analog signals?

Digital signals travel faster through copper wire Digital signals only need to be recognised as high or low, so noise must exceed the noise margin to cause an error Digital signals carry error-correcting parity bits automatically Digital signals have higher voltage levels that overwhelm noise

Convert the binary number 1011 to decimal.

9 11 13 14

What is the decimal number 25 expressed in binary?

10111 11100 11001 10011

One hexadecimal digit represents exactly how many bits?

2 bits 8 bits 4 bits 16 bits

What is the hexadecimal value 0x2A in decimal?

26 34 42 52

A 10-bit ADC measures voltages from 0 V to 5 V. What is the voltage resolution (smallest detectable voltage change)?

Approximately 50 mV Approximately 4.9 mV Exactly 10 mV Approximately 1.2 mV

The Nyquist theorem states that to accurately capture a signal, the sampling rate must be:

Equal to the highest frequency present in the signal At least twice the highest frequency present in the signal Ten times the highest frequency to avoid distortion At least half the highest frequency to save bandwidth

A DAC (Digital-to-Analog Converter) is used in a smartphone's audio output. What does it do?

Converts microphone sound into digital data for storage Converts the stored digital audio data into a continuously varying voltage that drives the speaker Increases the bit depth of low-quality audio files Samples the analog speaker signal to check for distortion

How many bytes are in one Megabyte (MB) using the binary definition used in computing?

1,000,000 bytes 1,024 bytes 1,048,576 bytes 8,388,608 bytes

An analog temperature sensor outputs a voltage between 0 V and 3.3 V representing −40 °C to +125 °C. What temperature does an output of 1.65 V represent?

0 °C 42.5 °C 62.5 °C 82.5 °C

What is the noise margin in a digital logic system?

The maximum signal frequency before the logic gate fails The amount of electromagnetic shielding around the PCB The voltage range a signal can deviate from its ideal level and still be correctly read as a 0 or 1 The minimum supply voltage required for the chip to operate

Why does audio on a CD sound better than audio transmitted over AM radio?

AM radio uses a lower carrier frequency, which limits its audio bandwidth CD audio is stored digitally with 16-bit resolution and 44.1 kHz sampling, capturing the full range of human hearing without noise CDs use higher voltage levels that reduce distortion AM radio compresses audio to fit more stations, reducing quality