Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Noise figure is a measure of how much thermal noise an amplifier adds to a received signal, expressed in decibels (dB). For a low-noise amplifier (LNA) operating at UHF frequencies, the goal is to add as little noise as possible. A typical modern, high-quality UHF preamplifier will have a positive noise figure of around 0.5 dB to 1 dB. You can easily eliminate several of the distractors by looking at the units. Noise figure is a ratio expressed in dB, not an absolute power level, which rules out the options using dBm. Additionally, because a real-world amplifier will always add at least some noise to a circuit, a noise figure cannot be negative, eliminating the -10 dB option.