Exam 350-401 topic 1 question 562 discussion

or the easiest calculation is using the laws of 3s covered in the book. A value of 3dB means that the power value of interest is double the reference value.

10*log(100) - 10*log(25) = 20dbm - 14dbm = 6dbm

A is correct 3+3 first 3 increase from 25 to 50 the other 3 increase from 50 to 100 each 3dB doubles the power

3+3 first 3 increase from 25 to 50 the other 3 increase from 50 to 100 each 3dB doubles the power

100 mW = 20 dBm 25 mW = 14 dBm = 20 dBm - 14 dBm = 6 dBm https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/23231-powervalues-23231.html

6 dbm Power Change dB Value = 0 dB × 2 +3 dB / 2 −3 dB × 10 +10 dB / 10 −10 dB

C. 17 dBm The power level of an AP can be measured in watts (W) or milliwatts (mW). To convert from mW to dBm, you can use the formula: dBm = 10 * log10 (mW). If we increase the AP power level from 25 mW to 100 mW, we can calculate the power difference in dBm as follows: 100mW = 0.1W 100mW = 10 * log10 (0.1W) = 10 * (-1) = -10 dBm 25mW = 0.025W 25mW = 10 * log10 (0.025W) = 10 * (-2.602) = -26.02 dBm Power difference = -10 dBm - (-26.02 dBm) = -10 dBm + 26.02 dBm = 16.02 dBm or approximately 17dBm