Answer:
1. Answer: (a) earthing
Explanation: The process of transferring of charge from a charged object to the earth is called earthing.
2. Answer: (c) richter scale
Explanation: The Richter scale measures the largest wiggle (amplitude) on the recording, but other magnitude scales measure different parts of the earthquake. The USGS currently reports earthquake magnitudes using the Moment Magnitude scale, though many other magnitudes are calculated for research and comparison purposes.
3. Answer: (b) Seismograph
Explanation: Seismic waves caused by an earthquake, other Earth-shaking phenomenon or explosion are recorded or measure using the instrument called Seismograph.
4. Answer: (d) Earthing
Explanation: Earthing is not a natural phenomenon. Types of natural phenomena include Weather, fog, thunder, tornadoes; biological processes, decomposition, germination; physical processes, wave propagation, erosion; tidal flow, a moonbow, blood moon, and natural disasters such as electromagnetic pulses, volcanic eruptions, earthquakes, midnight sun and polar night.
5. Answer: (a) 2
Explanation: There are two types of charges are gained by rubbing objects. They are positive and negative charges.
6. Answer: (d) Conducts electric charge to the ground when lightning strikes the building
Explanation: Lightning conductors are installed in buildings to provide a path for electric discharge during a lightning strike let them reach the ground and protect the building from a lightning strikes.
7. Answer: (a) a thunder
Explanation: Lightning always follows thunder because it depends on the speed of sound and light.
8. Answer: (c) an earthquake under the sea
Explanation: Tsunami is caused due to disturbance caused by deep down the sea. Lightening will not cause any disturbance for the sea whereas earthquakes, A major nuclear explosion undersea, and Volcanic eruption can cause a disturbance in the sea.
9. Answer: (a) seismic wave
Explanation: Seismic waves fall into two general categories: body waves which travel through the interior of the earth and surface waves which travel on the only at the Earth's surface.
10. Answer: (c) resin
Explanation: Amber is formed from resin exuded from tree bark, although it is also produced in the heartwood. Resin protects trees by blocking gaps in the bark. Once resin covers a gash or break caused by chewing insects, it hardens and forms a seal.
11. Answer: (a) Repulsion
Explanation: Repulsion is being considered as the sure test of charge on body as the induction of charge is possible between an uncharged body and charged body when brought close together.
12. Answer: (d) All of these
Explanation: Ebonite gets charged by rubbing on fur. Plastic also gets charged on rubbing by fur. and Amber also gets charged by rubbing on fur.
13. Answer: (b) They acquire equal and opposite charges
Explanation: When two bodies are rubbed against each other, some electrons are transferred from one body to another body. Hence one body has a deficiency of electrons and other body has an excess of electron by the same amount. Hence, one body acquire positive while other acquires negative charge of same magnitude.
14. Answer: (b) Positive
Explanation: It is a convention to call the charge acquired by a glass rod when it is rubbed with silk as Positive.
15. Answer: (c) Electroscope
Explanation: An electroscope is a device that is used for the detection and identification of charges on objects.
16. Answer: (d) lightning conductor
Explanation: When a building is hit by lightning, the lightning conductor conducts all charges straight into the Earth thus protecting the building from damage.
17. Answer: (d) Bhuj (Gujarat)
Explanation: The 2001 Gujarat earthquake, also known as the Bhuj earthquake, occurred on 26 January, India's 52nd Republic Day, at 08:46 am IST.
18. Answer: (b) Take shelter under short trees
Explanation: As the discharge of a huge amount of electric charge prefers the conductors of narrow cross-section, that is, pointed end, lightening always prefers to discharge through the pointed end. Hence, it is safe to take shelter under short trees instead of a single tall tree.
19. Answer: (b) repel each other
Explanation: Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge.
20. Answer: (c) earthquake
Explanation: An earthquake is an intense shaking of the Earth's surface. The shaking is caused by movements in Earth's outermost layer.
21. Answer: (d) Odisha
Explanation: In Orissa, major earthquakes are less likely to occur. Kashmir, the Western and Central Himalayas, the entire North-East, the Rann of Kutch, Rajasthan, and the Indo-Gangetic Plain are perhaps the most dangerous regions in India.
22. Answer: (b) thunder
Explanation: Lightning always follows thunder because it depends on the speed of sound and light.
23. Answer: (a) the Indian Ocean
Explanation: The tsunami wave struck havoc in the Indian Ocean on the 26 December 2004. The wave was the result of the earthquake that had its epicenter close to the western boundary of Sumatra. The magnitude of the earthquake was 9.0 on the Richter scale.
24. Answer: (a) loose
Explanation: Sparks on an electric pole when wires become loose. This phenomenon is quite common when the wind is blowing and shaking the wires. You might also have seen sparks when a plug is loose in its socket. Lightning is also an electric spark but on a huge scale.
25. Answer: (d) Conductor
Explanation: A conductor is any material that allows the passage of free electrons. Examples of conductors include copper and iron.
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