HVE Breakdown in Insulating Materials

What is the primary outcome of ionization in an insulating material?

• Creation of free electrons and positive ions.

• Formation of an insulating layer around the material.

• Neutralization of the electric field.

• Decrease in the conductivity of the material.

Which of the following best describes the de-ionization process?

• The separation of ions in the gas.

• The neutralization of ions by recombination with electrons.

• The generation of free electrons from neutral molecules.

• The breakdown of the insulating material due to high voltage.

Which type of discharge occurs when ionization is limited to a thin layer near an electrode, often seen in power lines?

• Corona discharge

• Townsend discharge

• Spark discharge

• Streamer discharge

According to Townsend's theory, the multiplication of electrons during breakdown occurs primarily through which process?

• Secondary electron emission from the cathode.

• The formation of ion pairs through collisions.

• The absorption of thermal energy by gas molecules.

• The recombination of free electrons and ions.

Which gas is most commonly used for insulation in high-voltage applications due to its low ionization potential?

• Oxygen

• Nitrogen

• Argon

• Hydrogen

What happens to the breakdown voltage in a uniform gap as the distance between the electrodes increases?

• Breakdown voltage decreases.

• Breakdown voltage remains constant.

• Breakdown voltage increases.

• Breakdown voltage fluctuates.

In the context of gas insulation, which of the following factors most affects the breakdown strength of the material?

• The density of the gas.

• The molecular weight of the gas.

• The temperature of the gas.

• The purity of the gas.

What distinguishes a non-uniform gap from a uniform gap in terms of electrical breakdown?

• Non-uniform gaps require higher voltage to break down.

• Non-uniform gaps have an uneven electric field, leading to easier breakdown.

• Uniform gaps break down more easily because of consistent ionization.

• Non-uniform gaps do not ionize at all.

Which of the following statements about Townsend's theory is correct?

• It is applicable only to non-uniform breakdown.

• It assumes a constant electric field in the breakdown region.

• It explains the breakdown of insulating materials in the presence of a uniform magnetic field.

• It is based on the concept of ionization by collision in gases.

In the streamer mechanism, what is primarily responsible for the rapid increase in the ionized region?

• The sudden increase in temperature within the insulating material.

• The avalanche effect from the free electrons.

• The creation of high-energy photons in the discharge process.

• The formation of a highly localized electric field that accelerates electrons.