Some Natural phenomena 8 Flashcards Preview

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Flashcards in Some Natural phenomena 8 Deck (42)
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1
Q

Tornados generally occur in the regions of

A

Atlantic Ocean

2
Q

Speed of tornadoes

A

Weak - 50 to 60 km per hr

Strong - 400 km per hr

3
Q

Speed of the wind is measured by

A

Anemometer

4
Q

Word monsoon derived from the word

A

Mausam (Arabic - means season)

5
Q

In America cyclones are referred as

A

Hurricanes

6
Q

In Philippines and Japan cyclones are referred as

A

Typhoon

7
Q

Gales

A

Winds moving at high speed

8
Q

In land , the crust has an average thickness of

A

40 km

9
Q

In oceans,the crust has an average thickness of

A

10-12 km

10
Q

Mantle length

A

2900 km (approx.)

11
Q

Density of mantle

A

Increases with depth - 3.5 to 5.5 gram/cm3

12
Q

Mantle contains

A

Silicate minerals rich in magnesium and iron.

13
Q

Outer core contains

A

Iron and nickel in molten state. Also sulphur

14
Q

Outer mantle thickness

A

2300 km

15
Q

Inner core thickness

A

1300 km

16
Q

Inner core contains

A

A solid ball made of iron

17
Q

Lithosphere

A

Crust and upper layer of mantle together called

18
Q

An Earthquake is the fracture in the

A

LITHOSPHERE

19
Q

The crust is divided into

A

7 large plates and several smaller ones

20
Q

Plate tectonics -

A

THEORY that tells that the surface of the earth is made of several lithospheric plates.

21
Q

Himalayas is believed to be formed by the collision of

A

Eurasian plate and Indian plate.

22
Q

A fault is

A

A crack in the Earth’s crust.

23
Q

Focus (seismology) -

A

Point where Earthquake occurs

24
Q

Epicentre situation

A

Above the focus of the Earthquake ; on the surface.

25
Q

San Andreas fault is situated in

A

California

26
Q

San Andreas Fault marks the boundary between

A

Pacific plate and North American Plate

27
Q

Seismograph also called

A

Seismometer

28
Q

The output in a seismograph called

A

Seismogram

29
Q

Mild Earthquake; Richter scale reading -

A

0 - 2.9

30
Q

An increase of 1 on Richter scale means

A

A 30-fold increase in energy.

31
Q

Liquefaction

A

Process by which water saturated soil ; loses strength and acts like a fluid.

32
Q

Bhuj earthquake , when ?

A

26 January 2001 in Gujarat (90000 people)

33
Q

Kashmir earthquake

A

Struck indo-Pakistan border on 8 October 2005, magnitude- 7.6. (50000 people)

34
Q

Some earthquakes in Nepal

A

25 April and 12 May 2015 (7.8-8.1)

35
Q

Most earthquake prone country

A

Indonesia

36
Q

San Andreas fault dimensions

A

1000 km long

9 metres deep

37
Q

An Indian state in which earthquake has a great chance of occurring

A

Gujarat

38
Q

Tsunami width and speed

A

Width - 100 to 200 km

Speed - 700 to 800 km/hr

39
Q

During lightning air is heated to

A

30,000 °C

40
Q

Position of charges in a cloud

A

-ve charges in base

+ve charges in top

41
Q

How much Electric current flows during a lightning strike

A

10000 - 20000 amperes

42
Q

Strobe effect

A

Brightening and dimming of lightning