Which decibel value most closely represents a power increase from 5 watts to 10 watts?

Decibels (dB) are used to express the ratio between two power levels rather than an absolute value. A fundamental rule of thumb in radio theory is that doubling the power output corresponds to a 3 dB increase. In this scenario, the power increases from 5 watts to 10 watts. Since 10 is exactly twice as much as 5, the power has been multiplied by two. Therefore, the increase is 3 dB. A common error is looking at the arithmetic difference between the wattages (10 - 5 = 5) and incorrectly guessing 5 dB, but decibels always measure the multiplication factor, not the added difference.