Electrical Machines and Circuits

The voltage e_o indicated in figure has been measured by an ideal voltmeter. Which of the following can be calculated?

Three identical amplifiers with each one having a voltage gain of 50, input resistance of 1 K$\Omega$and output resistance of 250 $\Omega$, are cascaded. The open circuit voltage gain of the combined amplifier is

An amplifier without feedback has a voltage gain of 50, input resistance of 1 K$\Omega$ and output resistance of 2.5 K$\Omega$. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2, is

In a full-wave rectifier using two ideal diodes, V_dc and V_m are the dc and peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier are

In the voltage regulator shown in the figure, the load current can vary from 100 mA to 500 mA. Assuming that the Zener diode is ideal (i.e., the Zener knee current is negligibly small and Zener resistance is zero in the breakdown region), the value of R is

A transmission line is feeding 1 Watt of power to a horn antenna having a gain of 10 dB. The antenna is matched to the transmission line. The total power radiated by the horn antenna into the free-space is

In the circuit shown, all the transmission line sections are lossless. The Voltage Standing Wave Ration (VSWR) on the 60W line is

A lossless transmission line is terminated in a load which reflects a part of the incident power. The measured VSWR is 2. The percentage of the power that is reflected back is

In the circuit shown below, the switch was connected to position 1 at t < 0 and at t = 0, it is changed to position 2. Assume that the diode has zero voltage drop and a storage time t_s For 0 < t$\le$ t_s , v_R is given by (all in Volts)