Thermal noise from a resistor is measured for a given bandwi

Thermal noise from a resistor is measured for a given bandwidth and at a temperature of Calculate noise power when the temperature is changed

Solution

noise Power P = vn^2 / R = 4k*T*dletaf

10 x 10^-17 = 4 * k * (273+30) * deltaf

4 * k *deltaf = 3.30 x 10^-19

a) for T = 273+40 = 313 K

P = 4 * k *deltaf * T = 3.30 x 10^-19 x 313 = 1.03 x 10^-16 W

b) for T = 273 + 80 = 353 K

P = 4 * k *deltaf * T = 3.30 x 10^-19 x 353 = 1.16 x 10^-16 W