List of top Electrical Machines Questions

The switch (S) closes at \( t = 0 \) sec. The time, in sec, the capacitor takes to charge to 50 V is _________ (round off to one decimal place). 

The op-amps in the following circuit are ideal. The voltage gain of the circuit is __________(round off to the nearest integer). 

In the system shown below, the generator was initially supplying power to the grid. A temporary LLLG bolted fault occurs at \( F \) very close to circuit breaker 1. The circuit breakers open to isolate the line. The fault self-clears. The circuit breakers reclose and restore the line. Which one of the following diagrams best indicates the rotor accelerating and decelerating areas? 

The transformer connection given in the figure is part of a balanced 3-phase circuit where the phase sequence is “abc”. The primary to secondary turns ratio is 2:1. If \( I_a + I_b + I_c = 0 \), then the relationship between \( I_A \) and \( I_{ad} \) will be: 

In the circuit shown below, if the values of \( R \) and \( C \) are very large, the form of the output voltage for a very high frequency square wave input is best represented by: 

In the circuit, \( I_{DC} \) is an ideal current source. The transistors \( M_1 \) and \( M_2 \) are assumed to be biased in saturation, wherein \( V_{in} \) is the input signal and \( V_{DC} \) is fixed DC voltage. Both transistors have a small signal resistance of \( r_{ds} \) and transconductance of \( g_m \). The small signal output impedance of this circuit is: 

In the circuit with ideal devices, the power MOSFET is operated with a duty cycle of 0.4 in a switching cycle with \( I = 10 \, \text{A} \) and \( V = 15 \, \text{V} \). The power delivered by the current source, in W, is:

\[ \text{(round off to the nearest integer).} \]

The I-V characteristics of the element between the nodes X and Y is best depicted by 

Assuming ideal op-amps, the circuit represents a