Some Natural Phenomena Flashcards
What is lightning?
Lightning is a natural electrical discharge that occurs during a thunderstorm when there is a buildup of electrical charges in the atmosphere.
How is lightning formed during a thunderstorm?
Lightning is formed when there is a difference in electrical charges between the Earth’s surface and the atmosphere. The discharge occurs in the form of a bright flash.
Name the safety measures to be taken during a thunderstorm
Safety measures during a thunderstorm include staying indoors, avoiding open fields, not taking shelter under trees, and staying away from water bodies.
Define thunder.
Thunder is the sound produced by the rapid expansion of air surrounding a lightning bolt. It is often heard during a thunderstorm.
Explain the process of a lightning conductor and its purpose.
A lightning conductor is a metal rod installed on buildings to protect them from lightning strikes. It provides a path for the lightning to travel safely to the ground, preventing damage to the structure.
What is an earthquake?
An earthquake is the shaking of the Earth’s surface caused by the sudden release of energy in the Earth’s crust, leading to seismic waves.
How are earthquakes caused?
Earthquakes are caused by the movement of tectonic plates beneath the Earth’s surface. When these plates grind against each other or collide, it releases energy in the form of seismic waves.
Differentiate between the focus and epicenter of an earthquake.
The focus is the point inside the Earth where the earthquake originates, while the epicenter is the point on the Earth’s surface directly above the focus.
Mention the safety measures during an earthquake.
Safety measures during an earthquake include “Drop, Cover, and Hold On,” staying indoors, away from windows, and finding a safe place to take shelter.
Define the term ‘earthquake-resistant structures.’
Earthquake-resistant structures are buildings and constructions designed to minimize damage during an earthquake by incorporating engineering techniques that absorb and dissipate seismic energy.
Explain the concept of earthing in the context of electrical safety.
Earthing is a safety measure where electrical appliances and circuits are connected to the Earth with a conductor. It helps in preventing electric shocks by providing a path for the current to flow safely into the ground.
What causes the phenomenon of static electricity?
The phenomenon of static electricity is caused by the transfer of electrons between two objects, leading to an imbalance in charges and the build-up of static electricity.
Describe the process of charging by friction.
Charging by friction occurs when two objects rub against each other, causing the transfer of electrons. The object gaining electrons becomes negatively charged, while the one losing electrons becomes positively charged.
Name some common examples of static electricity in daily life.
Common examples of static electricity include the attraction of a balloon to a charged object after rubbing it against hair, clothes clinging together after drying, and sparks when walking on a carpet in dry conditions.
How does a lightning conductor work as a safety measure?
A lightning conductor provides a preferred pathway for lightning to travel, directing the electrical discharge safely into the ground. This helps in preventing damage to structures and ensures the safety of occupants.
What are seismic waves?
Seismic waves are waves of energy that travel through the Earth’s layers during an earthquake. They are responsible for the shaking and vibrations experienced on the Earth’s surface.
Explain the Richter scale used to measure the magnitude of earthquakes.
The Richter scale is a logarithmic scale(not linear like decibel scale) that measures the magnitude of earthquakes. Each whole number increase on the scale represents a tenfold increase in amplitude and approximately 31.6 times more energy release. (4 to 6 means 1000 Times more destructive)
How can individuals contribute to electrical safety at home?
Individuals can contribute to electrical safety by avoiding overloading circuits, using appliances with safety features, checking for faulty wiring, and using proper electrical insulation.
What causes the phenomenon of static electricity?
Static electricity is caused by the transfer of electrons between two objects, leading to an imbalance in charges. This occurs when certain materials gain or lose electrons through friction, conduction, or induction.
Describe the process of charging by friction.
Charging by friction involves the rubbing of two objects together, causing the transfer of electrons from one object to another. The object that gains electrons becomes negatively charged, while the one losing electrons becomes positively charged. This imbalance in charges results in the phenomenon of static electricity.
Name some common examples of static electricity in daily life.
Common examples of static electricity include:
1.Clothes clinging together after being in a dryer.
2.Static shock when touching a metal object after walking on a carpet in dry conditions.
3.Hair standing on end after rubbing a balloon against it.
4.The attraction of dust to a TV or computer screen.
How does a balloon stick to a wall after rubbing it against hair?
When a balloon is rubbed against hair, electrons from the hair are transferred to the surface of the balloon, making the balloon negatively charged. The wall, which is initially neutral, becomes polarized as the electrons on the wall are repelled, leaving a positive charge. Opposite charges attract, causing the balloon (negatively charged) to stick to the wall (positively charged).
- What is a gold-leaf electroscope used for?
A gold-leaf electroscope is used to detect the presence and type of electric charges on an object.
Describe the construction of a gold-leaf electroscope.
A gold-leaf electroscope consists of a metal rod with a metal cap and two thin gold leaves attached. The rod is enclosed in a glass or metal case with an insulated handle.
