When the Volume Control on a Stereo System Is Increased $d b = 20 \log \frac { V _ { 2 } } { V _ { 1 } }$

Multiple Choice

When the volume control on a stereo system is increased, the voltage across a loudspeaker changes from V ₁ to V ₂ , and the decibel increase is given by $d b = 20 \log \frac { V _ { 2 } } { V _ { 1 } }$ Find the decibel increase if the voltage changes from 1.7 volts to 3 volts.

A) db = 4.9
B) db = 8.7
C) db = 7.2
D) db = 11.4
E) db = 3.8