With necessary sketch, Explain the mode of operation of chopper which is turn off due to external circuiť's current. Write its merits and demerits. 3:

Q4. A switch-mode power supply is to be designed with the following specifications: Va = 47 V + 10% Vo = 5 V Switching freq. f, = 100 kHz Pioad= 15 – 45 W A forward converter operating in a continuous-conduction mode with a demagnetizing winding (N3=N1) is chosen. Assume all components to be ideal except for the presence of transformer magnetization inductance. a. Calculate N/N1 if this turns ratio is desired to be as small as possible. b. Calculate the minimum value of the filter inductance.

Pls. write solution neatly

A two wire DC distributor AB, 1000 meter long, is supplied from both ends, 240 V at A and 242 V at B. There is a concentrated load of 200 A at a distance of 400 meter from A and a uniformly load 1.0 A/m between the midpoint and end B. Determine (i) the current fed at points A and B (ii) the point of minimum potential and (iii) voltage and this point. Consider cable resistance as 0.005 ohm per 1000 meter each core.

Q9) A single-phase 230V, 1kW heater is connected across l-phase 230V, 50Hz supply through an SCR. For firing angle delays of 45° and 90°, the power absorbed in the heater element are === and ()a. 453W, 230W b. 754.6 W, 230W c. 220 W, 500.65W d. 454.57W, 250W

18.a. An inductor whose reactance can be varied by supplying current through a separate DC winding is called a/anA. saturable reactor.B. reactance tube.C. current reactor.D. autotransformer.18.b. A typical value of a-c voltage provided by a transformer for the operation of a doorbell isA. 2 V.B. 24 V .C. 80 V.D. 120 V.

Need Help with parts 11 and 12 please.   Thank you

Which one of the following d-c machine losses is determined by applying a standard value rather thanby measurement?A. Friction and windage lossB. Core lossC. Copper lossD. Stray-load loss Note: I have doubts if it is the letter B or the letter D, can you help me in this question, thanks.

An ac LVDT has the following data; input 6.3V, output 5.2V, range ±0.50 cm. Determine: a) Plot of output voltage versus core position for a core movement going from +0.45cm to -0.03cm? b) The output voltage when the core is -0.35cm from the center? c) The core movement from center when the output voltage is -3V? d) The plot of core position versus output voltages varying from +4V to -2.5V.

1- Derive expression for the output rms voltage for single phase ac voltage controller  with resistive load