Digital signals and information

9.Which of the following is true about analog signals?

10.In a digital signal, what does 'sampling' refer to?

11.Which of the following devices most likely uses digital signals?

12.What is the main advantage of using digital signals for long-distance communication?

13.A digital audio recording is made by sampling an analog sound wave 44,100 times per second. Each sample is stored as a 16-bit value. How many bits are used to store one second of this audio?

14.The graph shows the voltage of a signal over time. Which statement about the signal is correct?

15.A student measures the voltage of a signal at a point in a circuit. The voltmeter reads 3.2 V. The circuit uses a logic family where voltages below 0.8 V are considered low and voltages above 2.0 V are considered high. What is the logical value of this signal?

16.A digital thermometer records temperature as a binary number. Which of the following is a digital representation of 25° Celsius?

17.A student says, 'Digital signals are better than analog signals because they are immune to noise.' Which statement best evaluates this claim?

18.In a digital communication system, a signal is transmitted over a noisy channel. The original signal is a binary sequence: 10110. Due to noise, the received signal is 10010. How many bits are in error?

19.A student sets up an experiment to compare analog and digital transmission of a sound wave. They send the same sound through an analog wire and through a digital system. Which observation would best show the advantage of digital transmission?

20.Which of the following is an example of a digital signal?

21.A digital signal has a data rate of 1 megabit per second (1,000,000 bits per second). How many bits are transmitted in 0.5 seconds?

22.A student records the voltage of a signal at regular intervals and gets these readings: 0.1 V, 0.2 V, 0.1 V, 4.9 V, 5.0 V, 4.9 V. If the threshold for high is 3.0 V, which readings represent a high state?

23.A digital image is made up of pixels, each stored as a 24-bit number. How many different colors can each pixel represent?

24.In a digital circuit, a clock signal has a frequency of 100 MHz (100 million cycles per second). How long is one clock cycle?

25.A student wants to compare how much noise affects analog and digital signals. They set up two identical audio transmissions: one analog and one digital. They add increasing amounts of electronic noise to both. Which observation would best demonstrate that digital signals are more immune to noise?

26.In a digital circuit, a clock signal has a frequency of 50 MHz. How long does it take for the clock to complete 10 cycles?

27.A student measures the voltage at a point in a digital circuit and gets a reading of 2.1 V. The circuit uses a logic family where voltages below 0.8 V are considered LOW and voltages above 2.0 V are considered HIGH. What is the logical value of this signal?

28.A digital image is stored as a grid of pixels. Each pixel uses 8 bits to represent its color. How many different colors can each pixel represent?

29.A student records the voltage of a signal at regular intervals and gets these readings: 0.1 V, 0.2 V, 0.1 V, 4.9 V, 5.0 V, 4.9 V. The threshold for HIGH is 3.0 V and for LOW is 1.0 V. Which binary sequence does this represent?

30.In a digital communication system, a signal is transmitted over a noisy channel. The original signal is the binary sequence: 10110. Due to noise, the received voltages are: 4.9 V, 0.2 V, 4.8 V, 0.1 V, 4.7 V. Using a threshold of 2.5 V (above is 1, below is 0), what is the received binary sequence?

31.A student sets up an experiment to compare analog and digital transmission of a sound wave. They send the same sound through an analog wire and through a digital wire. At the receiving end, they observe that the digital signal is identical to the original, but the analog signal has some distortion. What is the most likely reason?

32.A digital signal has a data rate of 2 megabits per second (2,000,000 bits per second). How many bits are transmitted in 3 seconds?

33.Which of the following statements about analog and digital signals is correct?

34.A student is designing a digital thermometer that measures temperature from -10°C to 40°C with a resolution of 0.5°C. How many bits are needed to represent all possible temperature readings?

35.The graph shows the voltage of a signal over time. The signal switches between 0 V and 5 V. Which statement about the signal is correct?

36.What is a digital signal?

37.A student records the voltage of a signal at regular intervals and gets these readings: 0.1 V, 0.2 V, 0.1 V, 4.9 V, 5.0 V, 4.9 V. The threshold for high is 3.0 V, and for low is 0.8 V. Which binary sequence does this represent?

38.In a digital communication system, a signal is transmitted over a noisy channel. The original signal is the binary sequence: 10110. Due to noise, the received signal is 10010. How many bits were corrupted?

39.A student sets up an experiment to compare analog and digital transmission of a sound wave. They send the same sound through an analog wire and through a digital wire with sampling. At the receiving end, they compare the two signals. Which result would best demonstrate the advantage of digital signals?

40.A student is designing a digital thermometer that measures temperature from -10°C to 40°C with a resolution of 0.5°C. How many bits are needed to represent all possible readings?