Sound intensity level dB & electromagnetic wave?

Question

1. A rock band's music has an average sound intensity level of 123 dB. What would the average level of intensity be if the intensity were reduced by a factor of 4?

(I want to decrease it by 12 so it would be 11dB, but iam not sure if that is right??)

2.An electromagnetic wave has a wavelength of 6 X 10^-12 m. In what region of the EM spectrum is this radiation?

(I think that it is in the gamma or the visible light, iam not sure, i need help??)

Answer 1

1. 93 dB = 1 watt

96 dB = 2 watt

99 dB = 4 watt

102 dB = 8 watt

105 dB = 16 watt

108 dB = 32 watt

111 dB = 64 watt

114 dB = 128 watt

117 dB = 256 watt

120 dB = 512 watt

123 dB = 1024 watt

126 dB = 2048 watt

2. gamma region

http://universe.nasa.gov/be/Library/EM_S...

: )