Multiple choice general knowledge A two-times increase or decrease in power results in a change of how many dB? 2 dB 3 dB 6 dB 12 dB Reveal answer Fill a bubble to check yourself B Correct answer Explanation A 3 dB change represents approximately double or half power because dB = 10log10(P2/P1). When power doubles (P2/P1=2), 10log10(2) ≈ 3.01 dB, commonly rounded to 3 dB.