In Focus

Electricity

1. What is an electric current.?
2. What makes lightning flash?
3. Why does your hair go frizzy?
4. What is a silicon chip?
5. What are the best conductors?

Deserts

1. What are dust storms?
2. Can water change desert scenery?
3. What are oases?
4. What are wadis?
5. What is desertification?

Seabirds

1. The emperor penguin which lives in Antarctica is the biggest penguin in the world. True | false?
2. What is a tropic bird?
3. How fast do penguins swim?
4. Which bird has the longest wings?
5. Which bird makes the longest migration?

[Answers]

Electricity

1 An electric current is a continuous stream of electrical charge . It happens only when there is a complete unbroken circuit for the current to flow through,typically a loop of copper wire..

2.Lightning flashes produce 100 million volts of static electricity.Lightning is created when raindrops and ice crystals inside a thundercloud become electrically charged as they are flung together losing or gaining electrons from each other. Negatively charged particles build up the base of the cloud . When this charge has built up enough, it discharges as lightning, either flashing within the cloud or forking between the cloud and the ground.

3. When you comb dry hair tiny electrons are knocked off to atoms in the comb as it rubs past. Your hair is coated with these tiny negative electrical charges and so is attracted to anything that has its normal quota of electrons or more. An electric charge made like this is called static because it does not move.

Try rubbing a baloon on your jumper to create a static charge,then you can stick it on the wall.

4. A silicon chip is an electronic circuit implanted in a small crystal of semi conducting silicon in such a way that it can be manufactured in huge numbers.

5. The best conductors are metals like copper and silver. Water is also a good conductor. Superconductors are materials like aluminium which is cooled until it transmits electricity almost without resistance.

Deserts

1. When desert winds sweep across the land it sweeps fine dust high into the air leading to choking dust storms.Wind from the Sahara in North Africa is often blown over southern Europe, carrying the pinkish dust with it.

2. Thousands of years ago many deserts were rainy areas and many land features were shaped by rivers. Flash floods sometimes occur in land areas that have become deserts.They sweep away much worn material giving new shape to the land.

3. Oases are places in deserts that have water supplies.Some oases have wells tapping ground water. Sometimes the water bubbles up to the surface in a spring.

4.Wadis are dry waterways in deserts. Travellers sometimes shelter in them at night. However,a freak storm can soon fill them with water and drowning can be a real danger.

5. When humans misuse land cutting down trees and overgrazing land these fertile land areas turn into deserts eventually. This process is called desertification.Natural climate change may also lead to desertification.This is how the Sahara desert was formed about 7,000 years ago.

Seabirds

1. True.It stands about 115 cm tall but it cannot fly like all penguins.

2. A seabird with two very long central tail feathers which flies over tropical oceans is called a tropic bird. There are three species of tropic bird.

3.Penguins are expert swimmers and divers. They can swim at speeds of 13 kmh but they may move even faster for short periods. They can also dive under water for a period of about two minutes or more. Some penguins are believed to be able to stay under water for up to 20 minutes.

4. The wandering albatross has the longest wings.When fully spread they measure up to 3.3 m from tip to tip.

5. The Arctic tern makes the longest migration. It makes a round trip of more than 35,000 km each year.

The birds nest in the Arctic during the northern summer and then travel south to escape the harsh northern winter, spending the southern summer near Antarctica where food is available in plenty during this time.

Win a valuable book from Books.lk

“Reading maketh a full man,” it is said and the importance of reading need not be reiterated. And, it is with the objective of promoting the habit of reading among children that the Junior Observer in collaboration with Bookazone (Pvt.) Ltd; the innovators of the country’s first web portal (www.books.lk), launched a competition in September.

We give a lucky reader an opportunity to win a valuable book priced at Rs 1000 from books.lk. All you have to do is answer a the question and mail it to the address given, on or before Friday of that week.

The name of each week’s winner will be published later.

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It allows you to purchase any title of book regardless of the author, publisher, or the country of origin. Although Bookazone web portal was limited to English users since 2009, the latest additions of Sinhala and Tamil is also accessible on www.poth.lk and www.puththagam.lk listing a wide range of books written and published in local languages in addition to what is offered in English apart from magazines, CDs and DVDs.

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So, keep improving your general knowledge to answer the question posed every week. And what better way to do so than by READING!

Winner of coupon No 10 is :
Jude Shannon Lucian,
66,N.H.S,Galmaduwa,
Kundasale.