301. Q. & A.s SCI. & TECH. – 13

Q. &  A.s  ‑‑‑  SCI.  &  TECH. – 13

346Q. Wind energy can save earth’s pollution annually. How much?

1.      215 million tonnes of CO₂.

2.      2,61,000 million tonnes of  SO₂.

3.      3,33,000 million tonnes of NO_x

347Q. What are the thermal power stations?

1.      Air pollution

2.      Water pollution

3.      Land degradation

4.      Noise pollution

348Q. Why can’t we arrest lightning for human use?

1. The first is that lightning is highly unpredictable. There is no way to know exactly where and when lightning will strike, so it would be difficult to find a location to turn into a facility for processing lightning for energy.
2. Lightning also delivers its energy all at once, which would require huge batteries and capacitors. Otherwise, the energy would simply blow out any systems established to capture it.
3. Lightning is so powerful that it would overload all but the most sophisticated and heavy-duty systems, and the wisdom of building and installing such a system would be questionable if it could only harvest the energy from a few lightning bolts a year.
4. Even in areas where lightning is frequent, the cost of the system would probably outweigh the benefit of getting electricity from lightning.
5. Lightning is simply not a good source of energy, and there are numerous alternatives which are safer, less energy-intensive, more effective, and readily available.

349Q. Why aren't the magnetic poles exactly at the geographic poles?
The magnetic pole is due to magnetic fields that are generated in the Earth's core. Because it is not a perfect dipole and has many local anomalies, the magnetic poles are not exactly at the geographic poles. Furthermore, in addition to a daily fluctuation related to interaction with the ionosphere and solar radiation, these fields change slowly, moving westward and flipping from south to north on a very long time scale. For that reason, the south magnetic pole is rarely found precisely at the real South Pole of the Earth. Because each layer of the ionosphere can reflect radio waves, daily fluctuations in it make for radio waves traveling farther in the hemisphere facing the Sun, and thus shortwave reception from places half a world away is better at night.

350Q. I'm flipping: you said magnetic poles flip?! How do we know that? Why do they flip? How often? How fast?
Because lava magnetizes according to the magnetic field prevailing on Earth at the time of solidification, and the magnetization of lava of different ages has been analyzed all over the globe. This method has also been used to track continental drift. The inversions are sudden (a few thousand years) compared to the length of periods between reversals (100's of thousands of yrs to millions of years). The distribution of times between reversals is quite irregular, having speeded up and now slowing down again. At the current rate of diminution of the field's intensity, there will be none in 2000 yrs. We may be in the middle of a flip. The mechanisms that govern the inversions are poorly understood.

351Q. How strong is the Earth's magnetic field?
6x10-5 Tesla at its strongest, near the poles. Although this includes effects of solar wind and other aspects of external origin, Gauss concluded in 1838 that most of it comes from the field of internal origin, predominantly a dipole.

352Q What is white dwarf?

A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy.

353Q. Why the height of the Himalayas is increasing? 

Once India was not near Asia. Due to continental drift theory, an island called India was drifting towards Asia, hit it, and started pushed ahead further. As Asia cannot move further the place that has been undergoing press is raising causing the Himalayas. This push is still continuing. So the height of the Himalayas is raising.

354Q  What is continental drift theory ?

If we dig the earth deep down how far can we go? The radius  of the earth is 6750 kms. Even if we can dig up to 50 kms, still there is a gap of 6700 kms. The continents are moving pieces on lava. Because of earths rotation, the continents are too drifting. This is called continental drift theory.

355Q Why the tropic cancer is 23 1/2  only?

The earth has oscillatory motion. The oscillation of the earth from 0^o  North to East and from zero degrees to West. This to and fro motion is called the oscillatory motion of the earth. This tilt is upto 23 ½^o. that is why tropic of cancer is 23 ½^o .

356Q  What is the geocentric theory?

In the olden days, it was believed that the earth was the centre of the universe. All the celestial bodies were going around the earth.  It was called  Geocentric theory.

357Q What is heliocentric ?

Geocentric theory was disproved. Then Copernicus proposed heliocentric theory. According to this theory the Sun is the centre of the solar system and all the planets go around the sun.

358Q What is AD and BC ?

BC indicates Before Christ. AD means Anno Domini. It is after Christ.

In BC the years counting is in descending order.

In AD the years counting is in ascending order.

359Q What is artificial Moon?

Russia launched a satellite and placed in 36,000 kms above the surface of the Earth called Geocentric orbit. After entering the orbit, at the bottom of the satellite a saucer like thing that unfolds to 65 metres in diameter. The height of the satellite is placed in such a way that except for few minutes, during the entire night the sun’s light is reflected to the ground.

This night light covers the entire Siberia.

360. Assassination of Gandhiji.

Killers were Day 1st Attempt 2nd Attempt 3rd Attempt 4th Attempt

1.      Nathoram Vinayak Godse 2.      Narayana Apte 3.      Gopal Godse 30-01-1948 25-6-1934, Pune Bomb exploded. No one died. No one was traced out. Nay 1944. Nadhu ram with a knife 9-9-1944 Godse with a knife 30-01-1948 He died.

361Q What is ESP?

ESP stands for Extra Sensory Perception.

The topics covered in this are

1.      Clairvoyance

2.      Telepathy

3.      Sleepology

4.      Dreamology

5.      Para-humanstate

6.      Sixth sense

7.      Saathapodi

Etc.

Its branch is located in Oxford University.

362Q What is 123 agreement?

According to USA’s norms regarding implementation of Nuclear reactors, fuel, testing, etc., are mentioned against 123 agreement.

India signed this agreement.

Along with India, 25 countries of this world have signed on  123 agreement.

Advantages :-

1.      Can purchase nuclear reactors

2.      Conduct nuclear tests

3.      Build bombs

4.      Share nuclear knowledge

Disadvantages:-

1.      Should not oppose US supremacy

2.      Surrender financially to US

3.      Reactors should be bought obnl,y from US

363Q What was Atlantis?

Atlantis was a large continent. It was as large as Asia and Europe kept together. It went down to the bottom of the sea in a night. The reasons are not known.

Aristotle gave a reference of this in “REPUBLIC”.

364Q What is wireless dead area?

There are some areas on the earth where wireless communication cannot be transmitted or received.

It may be due to solar wind.

It may be due to sun spot activity.

The reasons for this is still not yet known exactly.

365Q What is electronic warfare?

If we can jam on a frequency in wireless used by an enemy, the enemy  cannot communicate with their others. Communication is vital for success of a war. If that itself can break down that is victory. It is called electronic warfare.

366Q. Why electrical transmission line voltages are multiple of 11?

Alternating current voltage or current changes every instant. The values are measured in Peak value or Average value or Root Mean Square(RMS) value. RMS value is that value of a DC voltage which give the same heating effect of given AC voltage over a resistance load.

RMS value is 1.11 times average value. In early days of AC history probably multiples of 10 average values were selected. Later it was standardised to mention the RMS volts because RMS voltage multiplied by RMS current gives power in watts in every instant.

Hence earlier 10 KV average became 11 KV RMS. RMS is usually not mentioned because it is the normal nomenclature.

 

367Q.  What do you  mean by Power quality?

      The stability of the voltage and frequency supplied to customers varies among countries and regions. "Power quality" is a term describing the degree of deviation from the nominal supply voltage and frequency.

      Short-term surges and drop-outs affect sensitive electronic equipment such as computers. Longer-term outages, brown-outs and black outs and low reliability of supply generally increase costs to customers, who may have to invest in uninterruptible power supply or stand-by generator sets to provide power when the utility supply is unavailable or unusable.

      Erratic power supply may be a severe economic handicap to businesses who rely on   1. electrical machinery,

2. illumination, and

3. climate control.

368Q. The current frequency and voltage are inverse proportion.

At the end of the 19th century, Westinghouse in the US decided on 60 Hz and AEG in Germany decided on 50 Hz, eventually leading to the world being mostly divided into two frequency camps. Most 60 Hz systems are nominally 120 volts and most 50 Hz nominally 230 volts.

369Q What is the specialty of 14 January?

Sun begins ascending into Northern Hemisphere. It is a harvest festival.

“tamaso ma jyotiurgamaya” = may you top higher and higher.

The shortest day is Day 21/22 Winter solstice .

From that day onwards starts the longest days.

Uttarayana starts on Dec. 21.

Makarfa is the Raashi.

Earth’s tilt reaches 23 ½^o

A thousand years it was on Dec. 31.

After 2013, after 5,000 years it will be at the end of Feb.

After that after 9,000 years it will be in June.

In that year 15^th  January will be leap year.

370Q How can we find the depth of ocean?

Every ship has a SONAR at the bottom. It uses  Ultra Sonic waves. It sends these signals to the bottom, after touching the bottom it reflects back making a sound.

The time taken to this is 2t,

The velocity is known from the records

The distance travelled is 2d

V = d/t

In the case v = 2d/2t using this d can be calculated.