Some Natural Phenomena - I (2016)
Some Natural Phenomena (Set - II)
Questions
What happens when a glass rod, hard rubber and a plastic comb are rubbed with a piece of cloth?
- A static electric charge develops on the above said objects.
- Electric current starts flowing in any metallic object kept nearby.
- Lightning occurs.
- <font face="Arial">The objects become conductors.</font>
Why do hair stand on their ends when woollen clothes are taken off?
- Woollen clothes get charged and thus, they attract hair.
- The hair get entangled in spaces between the knitting.
- Woollen clothes are made up of natural fibres and as hair are natural fibres as well, they are attracted to each other.
- Woollen clothes are good conductors of heat, which makes them soft and sticky and thus, hair get stuck to them.
What causes lightning?
- Lightning is caused by the build up of electrostatic charge in clouds.
- Air is a bad conductor, but the presence of different impurities and impure water drops makes air partly conductive. It causes sparking from high tension wires which we perceive as lightning.
- Condensation of water in the clouds causes sparking due to release of energy which we perceive as lightning.
- When air blows, clouds collide with each other, which causes sparking due to friction, which we perceive as lightning.
What happens to the charged metal foils of an electroscope after touching them with a finger for some time?
- The two foils further repel each other.
- There is no effect of touching.
- Foils start attracting each other and get joined to each other.
- The foils come back to their original positions.
What type of charge is present in a charged plastic straw when rubbed with polyethene?
- Positive charge
- No charge
- Some positive and some negative charge
- Negative charge
Why earthing is required in electrical wires of buildings?
- To protect the electrical circuit from any power surge.
- To protect the building from electrical shocks due to any leakage of current.
- To charge the building and protect the building from lightning.
- To keep the electrical wires in place.
What happens to air current and water droplets during the development of thunderstorm?
- The air current moves upwards while water droplets move downwards.
- Both air current and water droplets move downwards.
- The air current moves downwards and water droplets move upwards.
- Both air current and droplets move upwards.
What causes an earthquake?
- Disturbances in upper side of the earth’s crust
- Disturbances deep inside the earth’s crust
- Disturbances deep inside the mantle
- Disturbances in the innermost part of the core
The movement of earth’s plates causes __________.
- very large scale dust storms
- earthquakes
- ocean storms
- <font face="Arial">very severe lightning storms</font>
Where do negative charges accumulate on the cloud?
- Upper edge of the cloud
- In the middle of the cloud
- Near the lower edge of the cloud
- On the whole surface of the cloud
The power of an earthquake is expressed in terms of a magnitude also known as _______.
- Richter scale
- Knots
- Intensity scale
- Decibels
The seismic waves are recorded by an instrument called ______.
- Seismology
- Seismograph
- Seismoscale
- Seismodegree
Which of the following devices is used to protect buildings from lightning?
- Lightning inductor
- Lightning wire
- Lightning conductor
- None of these
What should be avoided during a thunderstorm?
- Bathing
- Use of mobile phone
- Use of cordless phone
- Use of electrical lights
Earthquakes tend to occur at the weak zones and these weak zones are also called ________.
(a) Seismic zones
(b) Fault zones
(c) Tremor zones
- Only (a)
- Only (a) and (b)
- Only (c)
- Only (b)