Q. & A.s SCIENCE & TECH. – 10

Q. &  A.s  ‑‑‑  SCIENCE  &  TECH. – 10

271Q. Why should we learn English?

English is an imperialistic language.

All the languages of the world ended from development after explaining beauty.

English is the only language that entered science and technology.

It is an ever green language.

It is an enriching language.

It is ever revised.

272Q. How can bacteria communicate?

Bacteria can talk to each other via molecules they themselves produce. 

This is important when an infection propagates.

Now researchers are showing how bacerial control processes in human cells the same way.

273Q. What is the role of choke in tube light? [Blog ????  ]
When current discharges in tube, 254 nm UV light strikes the walls of the tube coated with fluorescent material phosphors gets converted to visible light with wavelength

400-700 nm.

The choke works like a step-up transformer producing nearly 1000 v so that electrical discharge takes place.

274Q. How does CFL [compact fluorescent lamps] work?

In CFLs stepping-up of voltage is not possible. The discharge is initiated by much compact electronic circuits integrated into the CFL holder.  These produce 10 KHz frequencies which can quick start of lamp as electrical discharge strikes faster at such high frequencies.

275Q. What is a top quark?  Blog ???? 

Top quark is 200 times massive than proton. It consists  an entire mass of gold.  Top quark consists 174 billion ev. It may be the heaviest particle nature has ever created.  This was formulated in 1960s. The collision  of trillions of   protons with anti-protons led to top quark.

276Q.  What are called quarks?  ???????

Quarters consist of six types. 1] up  2] down  3] charm  4] strange  5] top  6] bottom.

Quarks
Name	Symbol	Antiparticle	Charge (e)	Mass (MeV/c2)
up	u	u	+2⁄3	1.5–3.3
down	d	d	−1⁄3	3.5–6.0
charm	c	c	+2⁄3	1,160–1,340
strange	s	s	−1⁄3	70–130
top	t	t	+2⁄3	169,100–173,300
bottom	b	b	−1⁄3	4,130–4,370

277Q An aeroplane which goes in straight line travels in circle. Why?

An airplane travels in a straight line. But due to gravitational attraction it goes around the earth. That is why it seems circular.

278Q   Why an oil tanker is tied with a steel chain to the front, at the bottom?

When an oil tanker  travels due to friction electro static sparks are created. If they are neutralised every time it may catch fire.

279Q Why there are no A, B drives in “my computer”? 

A and B drives are floppy drives,

280Q. BERMUDEA TRIANGLES?    

Bermuda Triangle is an imaginary spread out in Bahama islamds. It is on the east side of Florida. There are many ships and aircrafts missing at that place. The reason is not known.

If we take the entire earth there are 12 places. The other famous place is Delvi’s sea. It is near to Japan.

281Q. WHY PROTONS LIVE IN A NUCLEUS?

Neutron  is the combination of proton and electron. Where protons come close, neutrons disintegrate into protons and electrons or vice versa. Proton becomes neutron or vice versa. As there are permanent protons and permanents neutrons the positive charges balance together.

282Q.Why pancreas cannot be transplanted?

Pancreas has many tubes [arteries and veins] which cannot be re-connected from the foreign pancreas.

283Q. WHY BETA RAYS ARE ELECTRONS? 

Neutron plays  a vital role in balancing the nucleus. Neutron disintegrates into proton and electron. Like a shuttle cock in the game it moves from one particle to another maintaining the protons from disintegrating. These electrons that come out are called beta rays.

284Q.  WHAT IS ESP?  

ESP stands for Extra Sensory Perception.

It consists about things beyond man’s perception.

1.      Para human state

2.      Telepathy

3.      Dreamology

4.      Sleepology

5.      Clairvoyance

6.      Sixth sense

285Q. Why honey can be preserved for hundreds of years?

Honey  consists of 7 % of maltose, 1%sucrose and less than 20% of water. Generally it is a bit  acidic [pH = 3 to 4].

It is a supercooled and mildly acidic liquid with a poor water content.

The biological decay is because a] the low pH  b] low water content  c] low nitrogenous [protein]  d] high viscosity of honey.

In many microorganisms the fructose meytabolism is rater less developed than the glucose.

Once even the mummies were preserved in honey.

286Q. Write different types of fire extinguishers?

There are four types of extinguishers;

1.      General  type  -           water, sand

2.      Oil type          -           foam

3.      Gas type          -           CO₂

4.      Electrical type -           CO₂, 

287Q.  WHAT IS ARTIFICIAL PETROL?

Carbon no. And product

1. 2. 3. 4. 5. 6. 7. 8.

C1 – C4 C5 – C7 C5 – C9 C9 -  C10 C10 – C16 C10 – C18 C17 – C30 C30 - …

LPG PETROLEUM ETHER GASOLENE NAFTHA KEROSENE DIESEL HEAVY OIL ASFALT

288Q.  What are the drawbacks of vacuum tubes?

1.      Lot of heat

2.      Tendency to burn out

3.      Big and bulky

4.      High current expenditure

5.      Large space

6.      High maintenance cost

289Q.  Why do we feel sleepy during boring classes?

In a boring during class room session, the student himself withdraws from the external stimulus and gradually goes to sleep. This reduces the sensory input and also activates the sleep centre. The brain gradually becomes less responsive to visual, auditory, and other environmental stimuli during the transition   from wake to sleep which is considered to be stage I of sleep.

290Q Condensed matter

The theory of particle physics applies to condensed matter physics as well; in particular, there are a selection of field excitations, called quasi-particles, that can be created and explored. These include:

• Phonons are vibrational modes in a crystal lattice.
• Excitons are bound states of an electron and a hole.
• Plasmons are coherent excitations of a plasma.
• Polaritons are mixtures of photons with other quasi-particles.
• Polarons are moving, charged (quasi-) particles that are surrounded by ions in a material.
• Magnons are coherent excitations of electron spins in a material.

291Q Why do we feel numbness in our legs when we sit down for a long time?

Numbness in legs is often associated with pricking or burnings sensation clinically it is

called as paresthesias temporary numbness or tingling that disappears quickly can occur when we sit with our legs crossed for a long time or sleeping on our arm in a bent position. Most people have felt this type of sensation. This sensation occurs due to no obvious stimulus. This type of very common numbness while recumbent or supine, poses no danger.

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292Q What is irradiation?

Irradiation is a method of preserving food. It involves bombarding food with gamma radiation, x-rays, or accelerated electrons to kill the micro-organisms that make food decay.

293Q How big is the Sun? 

The diameter of the Sun is 1,400,000 kilometres. That is 109 times the diameter of the Earth. The Sun's volume is 1,300,000 times that of the Earth, but its mass is only 330,000 times the mass of the Earth. 3,33,000 times of the Earth is one SUB.

294Q How can we measure the depth of  a ocean? ???

SONAR = sound and navigation and ranging.

SONAR is fitted to the bottom of a ship. When sound waves travel to the bottom of the ocean it strikes the bottom and reflects to the sonar.

D = [d₁ + d₂]/2

T = [t₁ + t₂]/2

Velocity = distance / time

There distance = velocity X time

295Q  What are wireless dead areas? 

The areas covering ships and planes experience this effect. The reason why this occurs is not known. Sometimes even sun spot activity can also cause this effect.