Before revision: If the resistor is at a physical temperature TR, then the Johnson–Nyquist noise power coupled to the amplifier input is PJ = kBTRB, where kB is Boltzmann’s constant, and B is the bandwidth.
After revision: If the resistor is at a physical temperature TR, then the Johnson–Nyquist noise power coupled to the amplifier input is PJ = kBTRB, where kB is the Boltzmann constant, and B is the bandwidth.