Describe bandwidth in relation to a radio channel and how it affects data rate.

• A. Data rate decreases.
• B. Data rate remains the same.
• C. If you increase bandwidth while keeping the same SNR, data rate increases.
• D. Data rate drops to zero.

Answer: (C)

Bandwidth is the width of the frequency range that a radio channel uses to carry information. A wider channel can carry more signal variations per second, which means more bits can be conveyed each second. When the signal-to-noise ratio is kept the same, increasing bandwidth increases the maximum achievable data rate, because there is more spectral space to encode information. In practice, this relationship is described by the idea that channel capacity grows with bandwidth at a given SNR, so you can transmit more data per second as the bandwidth expands. If you double the bandwidth while holding SNR constant, the potential data rate rises accordingly. The other options don’t fit because they imply no gain, a loss, or zero capability, which contradicts this capacity relationship.