Question 1: Determine the total R.M.S. voltage across a hundred ohm resistor placed as a load on a diode. With Tc = 1000 oC and go = .01mho, operating in the space-charge limited region. The bandwidth is as 5 KHz.
Question 2: The emission current of a temperature limited diode is 10 ma. Find out the R.M.S. value of the fluctuations component of the current in 20 KHz bandwidth.
Question 3: This is convenient to interpret the noise in a triode as being due to noisy resistor in series with the grid of a noise free value. Compute the value of this noisy resistor for a triode with mutual conductance of 2.6mA/V.
Question 4: A mixer phase consists of noise figure of 20db and this is preceded by an amplifier which has a noise figure of 9 db and an available power gain of 15db. Compute the overall noise figure referred to input.
Question 5: The equivalent noise temperature of cooled parametric amplifier is 20 degree Kelvin. Determine the noise figure.
Question 6: A radio receiver, joined to an antenna whose resistance is 50 ohm has an equal resistance of 50 ohm. Compute the receiver’s noise figure in db and its equal noise temperature at a supposed temperature.
Question 7: The noise figure of an amplifier at room temperature is .2db. Determine the equal temperature.
Question 8: The first period of a two phase amplifier has a voltage gain of 10, a 600 ohm input resistor, a 1600 ohm equivalent noise resistance and 27 ohm output resistance. For second phase these values are 25 ohm, 81 kohm, 10 kohm and 1 Mohm correspondingly.
Compute the equivalent noise resistance of this phase amplifier.
Question 9: The input resistor of the first phase of two phase amplifier is 600 ohm. The equivalent input noise resistance of these two phase amplifier was found to be 2.518 k ohm. Compute the noise figure of the amplifier if it is drawn by generator whose output resistance is 50 ohm.
Question 10: An amplifier operating over the frequency range from 1 to 20 MHz consists of a 10 kohm input resistance. Determine the RMS noise voltage at the input to this amplifier if the ambient temperature is 27oC?