Bit duration, bit rate problem

[Nipuna56]

Hi friends
1) I want to know what is bit duration and how to calculate 2 Mbps signal's bit duration

2) What is the bit rate (i want to know it's simple meaning)

3) source signal power 10W and receiver signal power 10 mW how to calculate attenuation

 

[preethi_k4]

1. bit duration is the time for the value remain as '1 ' or '0' or 'x value'
2. Bit rate indicates how fast the value of bit changes or how frequently the value of bit changes.
check this link https://wiki.answers.com/Q/What_is_the_duration_of_each_bit_if_the_bit_rate_of_a_signal_is_2Mbps
3. dB = 20 * Log(Vout / Vin)