Lightning Conductors and Earthing Systems
Learn about lightning conductors, their design, components, and how they protect buildings from lightning strikes. Topics include earthing systems, electrical safety, and the science behind lightning protection.
Questions
State whether given statement is True or False.
Charges are incapable of passing from clouds to lightning rod.
- True
- False
What are may happen if a building does not have earthing?
- Lightning may strike a building due to opposite charge causing fir or damage to the building
- In the rainy season water increases the chances of lightning striking a building causing damage
- Both A & B
- None of the above
What is earthing?
- Passage of large electric current resulting from a lightning into the earth
- Burying electric charge into the earth
- Preventing electric charge from entering the earth
- None of the above
Two types of earthings are provided: (a) Equipment earthing and (b) Neutral point earthing. Equipment earthing is provided for
- Safety of human being
- Safety of equipments
- Safety of starters and cables
- None
A lightning conductor installed in a building
- does not allow the lightning to fall on the building
- repels the lightning
- forces the lightning to fall in an area where there are no buildings
- conducts electric charge to the ground when lightning strikes the building
Lightning conductor is made up of conducting materials.
- True
- False
Lightning conductors are used to save the building from earthquakes.
- True
- False
Buildings are more susceptible to a lightning strike because
- they are higher than their surroundings.
- roofs of buildings are wet in rainy season and hence become good conductors of electricity.
- the top of the building is wet and acquires an opposite charge to a cloud passing over the top by induction.
- All of the above.
Lightning strikes building when induced charge on top building is too high. This statement is:
- True
- False
Why are lightning conductors pointed in shape?
- To reduce mass.
- It attracts more electric charge due to very small radius and hence surface area.
- It allows more current.
- It repels the incident lightning discharge.
A lightning conductor consists of
- several sharp metal spiked connected to a thick copper strip.
- a metal plate buried deep inside the ground connected to the ground end of copper strip.
- a conductor fixed on top of the building.
- all of the above
The lightning conductor used in building, protects the building by :
- dissipating the electric charge away from the building
- conducting the lightning safely to the ground
- absorbing the electric charge
- None of these
Which of the following correctly represents the sequence of operations of isolator circuit breaker and earthing switch while opening a circuit :
- close earthing switch - open circuit breaker open isolator
- open isolator - close circuit breaker - open earthing switch
- open circuit breaker - open isolator - close earthing switch
- close circuit breaker - close isolator - open earthing switch
What is the main function of lightning conductor?
- To capture lightning stroke and conduct discharge current safely to the ground
- To capture lightning stroke and conduct discharge current safely to the cloud
- To capture lightning stroke and conduct discharge current safely to the building
- None
Which of the following correctly presents the sequence of operations of isolator circuit breaker and earthing switch while closing a circuit :
- Ensure circuit breaker is closed - close isolator - open earthing switch
- Ensure circuit breaker is open - close isolator - open earthing switch if any close circuit breaker
- Ensure circuit breaker is open - open isolator - open earthing switch if any close circuit breaker
- None of the above
- True
- False
Which one of the following statements is CORRECT?
- Lightning rods are made of insulators
- A conductor holds charge
- The earth is an insulator
- An insulator prevents charge from flowing
The lightening conductor is connected to interface with ground or "earth" through
- a cathode
- an anode
- an electrode
- a semiconductor
is engineered to protect an elevated structure in the event of lightning strike.
- A lightning conductor
- Copper wire
- A lightening shield
- All of the above
Where is the lower end of a lightning conductor fixed in the building?
- at the top
- at a window
- at the base
- in the ground