Calculate the breakdown voltage, breakdown field strength and Townsend's first ionization coefficient of an air-insulated electrode system having an electrode spacing of a = 3.0 cm at T= 273 °K and p = 760 Torr (A(T = 273 °K) = 24.4 1/cm.Torr , B(T = 273 °K) = 341.6 V/cm.Torr, y = 1/5000). b) What can you say about the accuracy of the calculations, why? c) Calculate the critical pressure and corresponding breakdown voltage and breakdown field. d) Calculate the discharge voltages at a high pressure (4 atmosphere) and a very low pressure, (0.2 Torr). If you were to design a high voltage insulation system, what would be your choice: Normal pressure (760 Torr), high pressure (4 atmosphere) or very low pressure (0.2 Torr), why?

Calculate the breakdown voltage, breakdown field strength and Townsend's first ionization coefficient of an air-insulated electrode system having an electrode spacing of a = 3.0 cm at T= 273 °K and p = 760 Torr (A(T = 273 °K) = 24.4 1/cm.Torr , B(T = 273 °K) = 341.6 V/cm.Torr, y = 1/5000). b) What can you say about the accuracy of the calculations, why? c) Calculate the critical pressure and corresponding breakdown voltage and breakdown field. d) Calculate the discharge voltages at a high pressure (4 atmosphere) and a very low pressure, (0.2 Torr). If you were to design a high voltage insulation system, what would be your choice: Normal pressure (760 Torr), high pressure (4 atmosphere) or very low pressure (0.2 Torr), why?

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter1: Atomic Structure

Section: Chapter Questions

Problem 6RQ: How many valence electrons are generally contained in materials used for insulators?

See similar textbooks

Similar questions

8. Liquids with solid impurities a) Have higher dielectrie strength b) Of large size have higher dielectric strength c) Have lower dielectric strength as compared to pure liquids d) None of the above 9. Peak to peak ripple is defined as a) the difference between average de voltage and peak value b) the difference between maximum and minimum de voltage c) the difference between maximum ac and average dc voltages d) the difference between ac (rms) and average de voltages 10. In a Cockroft-Walton circuit, input voltage 100 kV load current 25 mA, supply frequency 100 Hz, each capacitor 10 nF. The optimum no. of stages for maximum output voltage is a) 1 b) 2 c) 10 d) 35
2. When a current of 1A flows through a wire, the drift velocity of the electrons is 0.9 mm/s. What will be the drift velocity of the electrons when a 2A current flows through another wire of the same material having double the length and double the area of cross section and same temperature.
We want to investigate how the field strength will be with air as dielectric and with steatite. A plate capacitor is placed in a 24 kV network between phase and ground. The relative permittivity of air is &=1 and for steatite &-6. The plate capacitor has area = 1m². The distance between the electrodes is 2 mm. Ep = 8.854-10-12 F/m A=1m² d=2mm a) Calculate the maximum field strength in the plate capacitor. (Answer: 9.8kV/mm) b) What is the capacitance of the capacitor if we use steatite? (Answer: C = 26.6nF)
7. Each of three insulators forming a string has self-capacitance of "C farad. The shunt capacitance of each cap of insulator is 0-25 C to earth and 0-15 C to line. Calculate the voltage distribution across each insulator as a pecentage of line voltage to earth and the string efficiency. [31-7%, 29-4%, 38-9%; 85-7%]
n 10 (based on material in Unit 23) Based on the band theory of solids, briefly explain the difference in electrical conductivity between semiconductors and insulators at a given temperature.
Q. 17. In secondary ionization by photons: A. Electrons are emitted from the cathode. the gas molecules. C. The electrode work function needs to be very large. D. None of the above B. The photons give their energy to growth when voltage is applied across Q. 18. According to Townsend observations on the c parallel plates of a capacitor: A. The current first increases proportionally due to secondary ionization process. B. Close to breakdown, the current increases proportionally due to ionization by collision. C. After reaching self-sustained discharge, the current needs to go to infinity. D. All of the above
Neglecting losses and fringing effects and assuming the substrate of a stripline to have a thickness of 0.42 (mm) and a dielectric constant of 2.83, determine the required width (in mm) of the metal strip in order for the stripline to have characteristics resistance of 78 Ohms. No need for a solution. Just write your numeric answer in the space provided. Round off your answer to 2 decimal places.
What is the conductivity of AWG #32 tungsten wire with a resistance of 0.0172 Q/cm? The diameter of AWG #32 is 8.0 mils. Ans. 17.9 MS/m 6.34.
A nickel chromium alloy conductor of resitance 24 ohms is 110 inches long and has a resistivity of 640 ohms-CM/ft. Determine its diameter.
A wire has a circular cross-section of radius r= 3.53 mm. The conductivity of the wire is 1x10^5 (Ohm, meter) and its lengthis 2m. The total resistance of the wire in Ohms is:O a. 0.51O b. 0.72ç. 0.26O d. 5136.07O e. 797497.60
4.) Determine the conductance at 20°C of an aluminum bus bar 0.3 in.
7. Each of three insulators forming a string has self-capacitance of "C farad. The shunt capacitance of each cap of msulator is 0 25 C to earth and 0-15 C to line. Calculate the voltage distribution across each insulator as a pecentage of line voltage to earth and the string efficiency.