Question 1

Which of the following decreases within turn decreases the charging rate?&#10;A)temperature&#10;B)pressure&#10;C)enthalpy&#10;D)entropy

Accepted Answer

Temperature directly affects the charging rate of batteries; as temperature decreases, the charging rate typically decreases due to slower chemical reactions within the battery.

Question 2

Which of the following causes the corrosion of terminals and clamps?&#10;A)spilled electrolyte&#10;B)increase in temperature&#10;C)decrease in pressure&#10;D)due to high current

Accepted Answer

Spilled electrolyte causes corrosion of terminals and clamps because it is acidic and can react with the metal, leading to corrosion.

Question 3

Grounding transformer is used where neutral .........available&#10;A)is&#10;B)is not&#10;C)either a or b&#10;D). none of the above

Accepted Answer

Grounding transformers are used in situations where a neutral point is not available and needs to be artificially created to facilitate grounding.

Question 4

In equipment grounding, the enclosure is connected to ...........wire&#10;A)ground&#10;B)neutral&#10;C)phase&#10;D)either a or b

Accepted Answer

The enclosure is connected to the ground wire to ensure safety by providing a path for fault current to the earth, preventing electric shock.

Question 5

Earthing is necessary to give protection against&#10;A)danger of electric shock&#10;B)voltage fluctuation&#10;C)overloading&#10;D)high temperature of the conductors

Accepted Answer

Earthing provides a path for electrical current to dissipate into the earth, reducing the risk of electric shock to individuals by preventing the build-up of voltages that could be hazardous.

Question 6

In case of earth fault, the underground neutral system----------------lead to arcing ground&#10;A)does&#10;B)does not&#10;C)any of above&#10;D)none of above

Accepted Answer

An underground neutral system can lead to arcing ground in case of an earth fault because the neutral is not directly grounded, allowing voltage to build up and cause arcing.

Question 7

The advantage of neutral earthing&#10;A)safety of personnel&#10;B)reduction of earth fault current&#10;C)elimination of arcing ground&#10;D)none of the above

Accepted Answer

The answer of The advantage of neutral earthing&#10;A)safety of personnel&#10;B)reduction...

Question 8

In a substation the equipment used to limit short circuit current level is&#10;A)series reactor&#10;B)coupling capacitor&#10;C)lightening switch&#10;D)isolator.

Accepted Answer

Series reactors are used in substations to limit the short circuit current level by adding impedance to the circuit.

Question 9

In a star connected system without neutral grounding, zero sequence currents are&#10;A)zero&#10;B)phaser sum of phase currents&#10;C)same as rms value of phase currents&#10;D)same as peak value of phase currents

Accepted Answer

In a star-connected system without neutral grounding, zero sequence currents cannot flow because there is no return path for them. Therefore, the zero sequence currents are zero.

Question 10

Grounding transformer is used where neutral&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;available&#10;A)is&#10;B)is not&#10;C)any of above&#10;D)none of above

Accepted Answer

Grounding transformers are used where a neutral point is not available and need to be created to facilitate grounding. They provide a return path for fault currents to a neutral point in systems that are otherwise ungrounded.

Question 11

Ground resistance value for sensitive installations is&#10;A)less than 5 ?&#10;B)more than 5 ?&#10;C)equal to 50 ?&#10;D)any of above

Accepted Answer

The answer of Ground resistance value for sensitive installations is&#10;A)less...

Deck 4: Understanding Grounding and Earthing in Electrical Systems