please solve parts 31 and 32 Q28. A coaxial cable with a conductor surrounded by two dielectric layers. The radius of theconductor is 0.9 cm. The first dielectric layer has a 1.3 relative permittivity and 4.7 mm thickness. Ifthe second layer has a 3.5 mm thickness and was selected to maintain the same maximum electric fieldvalue, find the field value at the middle of the second layer if the applied voltage is 29 kV.A) 2.09 kV/mm B) 2.79 kV/mmD) 3,19 kV/mmC) 3.39 kV/mmQ29. Following measurements are made for a test specimen with a 7 kV rms supply at a frequency of6 kHz: The air capacitance of the electrode system-30 nF with negligible loss angle. The capacitanceand loss angle of the electrodes with specimen are 130 nF and 0.0066 respectively. Assuming there isno additional stray capacitance, determine the dielectric loss factorA) 0.975 pm (B) 0.253 pF/mC) 0.624 pF/mD) 0.080 pF/mQ.30. A solid dielectric exposed to high voltage in a laboratory to determine its mechanicalbreakdown strength. The dielectric has 0.97 GPa Young's modulus and relative permittivity & 2.2. Ifthe breakdown occurs when the applied voltage reaches 13 MV, determine the initial thickness of thedielectric.A) 3.07 mmB) 3.32 mmC) 2.57 mmD) 2.82 mmAssuming a fixed distance between parallel plates with a uniform field, and assuming unchangedTownsend's coefficients, the pressure is changed, and the breakdown voltage is measured withthe following results:At a pressure 650 torr the breakdown voltage is found to be 320 V. At a pressure 850 torr, thebreakdown voltage is found to be 370V.Answer Q31 & Q32Q.31. Find the value of the pressure for minimum breakdown voltage according to Paschen's law.A) 227.88 torr B) 229.88 torr C) 223.88 torrD) 225.88 torrQ. 32. Find the value of the minimum breakdown voltage according to Paschen'sA) 231.77 V B) 227.77 VC) 233.77 VD) 229.77 VQ. 33. A cable is tested for partial discharge using the traveling wave technique. If the cable length is119 km and the velocity of signal propagation in the cable is 0.26 km/us. And the time differencebetween the pulses measured at the detector at the end of the cable is 220 us. Find the location of thepartial discharge point from the receiving end.A) 88.4 kmB) 84.4 kmC) 90.4 kmD) 86.4 kmA 3-phase transmission line has conductors 1.4 cmindiameter spaced 1 m apart in anequilateral formation. If a current wave of 9 A travels along the line, and the line is connected atthe end to a second transmission line with a surge impedance of 470 22, answer Q34 & Q35:Q. 34. If the resistance and leakance are negligible, calculate the reflected phase voltage value (V):A) 626.6 V B) 576.6 VC) 651.6 VD) 601.6 VQ. 35. If the second transmission line has a resistance of 5per km and a leakance of 0.9 μ S per km,and if the line is 50 km long and is terminated at the end of the line by a 900 2 star connected load.Find the value of the reflected current wave at the end of the line.A) 2.6 AB)-2.08 AC) -1.66 AD)-3.24 A An experiment in a certain gas to find Townsend's coefficients resulted in the curve shown in thefig. 2 where d is the distance between the plates, and I is the current. the field value was keptfixed throughout the experiment. Answer questions Q21 & Q22.Q. 21. If the labeled slope is 9/cm, the steady-state current is 0.5 nA at d-0.2 cm. The critical thresholddistance for sustained discharge is 0.8 cm. Find the current when d-0.75 cm noting that at this distancethe curve is out of the linear range.A) 192.65 NA B) 190.65 nAC) 188.65 nA(D) 194.65 NAQ. 22. If the critical threshold distance for sustained discharge is d-0.77 cm, the value of Townsend'ssecond ionization coefficient is 0.102%, and the steady-state current is 0.57 nA at d-0.4 cm. And if thecurrent after increasing the distance is 1.22 nA, find the percentage of the supply voltage incrementassuming you are working in the linear range.A) 17.3%B) 23.3%D 21.3%Sloped1dC) 19.3%C',RawEN, Rp1(t)0Fig. 2Fig. 3Fig. 4Fig. 5Q. 23. For the transformer ratio arm bridge shown in Fig. 3, C's-200 nF, Ra-137.5 M2, Rp 10 G,and Cp-20 nF. What of the following could be the ratio Na: Nb to balance the bridge.(A) 110: 690C) 100: 680B) 140: 670D) 150: 680vo(t)Q. 24. A 4 kV, 110 Hz Schering bridge with a grounded detector as shown in fig. 4 has Cs-100 pF. Ina test on an insulator, the balance was obtained with C4-0.2 μF, R4-210 52, and R3= 140 2. Byremoving the insulator from the measuring system, the balance will be reached at R3=700 £2 andC4-0.004 µF. Consider the system stray capacitance and leakage and find the insulator parallelresistance Rp.:Α) 306.62 ΜΩΒ) 316.62 ΜΩC) 326.62 ΜΩD) 336.62 ΜΩQ. 25. A Rogowski coil is required to measure a 2 A current at a frequency of 4 kHz. The voltmeter isconnected across the integrating circuit shown in the Fig. 5. For proper integration, the circuit timeconstant RC is selected to be 10 times less than the period of the wave. If the coil has an effective areaof 103 m², an axial length of 0.3 m, and 100 turns, find the reading of the voltmeter:A) 41.9 mV B) 52.38 mV C) 26.82 mVD) 33.52 mVQ. 26. A solid dielectric of 1 cm thickness and relative permittivity &, 3.3 has an internal void filledwith air which breaks down at 30kV/cm. If internal discharge occurs when the applied voltage reaches8.3 kV rms, determine the thickness of the void.A) 1.07 mmB) 0.67 mmC) 1.27 mm(D) 0.87 mmQ. 27. A specimen is tested for insulation resistance by the loss of charge method. The specimencapacitance is 2.8 nF. It is observed that after charging, the voltage falls to half the initial value in oneminute. If the voltmeter used is assumed with infinite resistance, determine the insulator resistance.A) 44.14 G B) 27.08 GC) 30.91 GND) 90.48 GN

Answered: Image /qna-images/answer/57677c04-6e24-4886-9f14-1c82c3d80f3e.jpg

Answered: Assuming a fixed distance between…

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...