Thursday, February 25, 2021
10:17 AM (GMT +5)

Go Back   CSS Forums > CSS Compulsory Subjects > General Science & Ability

Reply Share Thread: Submit Thread to Facebook Facebook     Submit Thread to Twitter Twitter     Submit Thread to Google+ Google+    
LinkBack Thread Tools Search this Thread
Old Wednesday, April 04, 2012
zuhaib ahmed's Avatar
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason:
Join Date: Aug 2011
Location: Lahore
Posts: 1,080
Thanks: 1,226
Thanked 1,991 Times in 631 Posts
zuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud ofzuhaib ahmed has much to be proud of
Default Everyday science quiz!

1. Question: A man with a load jumps from a high building. What will be the load experienced by him?
Answer: Zero, because while falling, both the man and the load are falling at the same acceleration i.e. acceleration due to gravity.

2. Question: A piece of chalk when immersed in water emits bubbles. Why?
Answer: Chalk consists of pores forming capillaries. When it is immersed in water, the water begins to rise in the capillaries and air present there is expelled in the form of bubbles.

3. Question: Why does a liquid remain hot or cold for a long time inside a thermos flask?
Answer: The presence of air, a poor conductor of heat, between the double glass wall of a thermos flask, keeps the liquid hot or cold inside a flask for a long time.

4. Question: Why does a ball bounce upon falling?
Answer: When a ball falls, it is temporarily deformed. Because of elasticity, the ball tends to regain its original shape for which it presses the ground and bounces up (Newton's Third Law of Motion).

5 Question: Why is standing in boats or double decker buses not allowed, particularly in the upper deck of buses?
Answer: On tilting the centre of gravity of the boat or bus is lowered and it is likely to overturn.

6. Question: Why is it recommended to add salt to water while boiling dal?
Answer: By addition of salt, the boiled point of water gets raised which helps in cooking the dal sooner.

7. Question: Why is it the boiling point of sea water more than that of pure water?
Answer: Sea water contains salt, and other impurities which cause an elevation in its boiling point.

8. Question: Why is it easier to spray water to which soap is added?
Answer: Addition of soap decreases the surface tension of water. The energy for spraying is directly proportional to surface tension.

9. Question: Which is more elastic, rubber or steel?
Answer: Steel is more elastic for the same stress produced compared with rubber.

10. Question: Why is the sky blue?
Answer: Violet and blue light have short waves which are scattered more than red light waves. While red light goes almost straight through the atmosphere, blue and violet light are scattered by particles in the atmosphere. Thus, we see a blue sky.

11. Question: Why Does ink leak out of partially filled pen when taken to a higher altitude?
Answer: As we go up, the pressure and density of air goes on decreasing. A Partially filled pen leaks when taken to a higher altitude because the pressure of air acting on the ink inside the tube of the pen is greater than the pressure of the air outside.

12. Question: On the moon, will the weight of a man be less or more than his weight on the earth?
Answer: The gravity of the moon is one-sixth that of the earth; hence the weight of a person on the surface of the moon will be one-sixth of his actual weight on earth.

13. Question: Why do some liquid burn while others do not?
Answer: A liquid burns if its molecules can combine with oxygen in the air with the production of heat. Hence, oil burns but water does not.

14. Question: Why can we see ourselves in a mirror?
Answer: We see objects when light rays from them reach our eyes. As mirrors have a shiny surface, the light rays are reflected back to us and enter our eyes.

15. Question: Why does a solid chunk of iron sink in water but float in mercury?
Answer: Because the density of iron is more than that of water bus less than that of mercury.

16. Question: Why is cooking quicker in a pressure cooker?
Answer: As the pressure inside the cooker increases, the boiling point of water is raised, hence, the cooking process is quicker.

17. Question: When wood burns it crackles. Explain?
Answer: Wood contains a complex mixture of gases and tar forming vapors trapped under its surface. These gases and tar vapors escape, making a cracking sound.

18. Question: Why do stars twinkle?
Answer: The light from a star reaches us after refraction as it passes through various layers of air. When the light passes through the earth?s atmosphere, it is made to flicker by the hot and cold ripples of air and it appears as if the stars are twinkling.

19. Question: Why is it easier to roll a barrel than to pull it?
Answer: Because the rolling force of friction is less than the dynamic force of sliding friction.

20. Question: If a feather, a wooden ball and a steel ball fall simultaneously in a vacuum, which one of these would fall faster?
Answer: All will fall at the same speed in vacuum because there will be no air resistance and the earth?s gravity will exert a similar gravitational pull on all.

21. Question: When a man fires a gun, he is pushed back slightly. Why?
Answer: As the bullet leaves the nozzle of the gun?s barrel with momentum in a forward direction, as per Newton's Third Law of Motion, the ejection imparts to the gun as equal momentum in a backward direction.

22. Question: Ice wrapped in a blanket or saw dust does not melt quickly. Why?
Answer: Both wood and wool are bad conductors of heat. They do not permit heat rays to reach the ice easily.

23. Question: Why do we perspire on a hot day?
Answer: When the body temperature rises, the sweat glands are stimulated to secrete perspiration. It is nature's way to keep the body cool. During the process of evaporation of sweat, body heat is taken away, thus giving a sense of coolness.

24. Question: Why does ice float on water but sink in alcohol?
Answer: Because ice is lighter than water it floats on it. However, ice is heavier than alcohol and therefore it sinks in alcohol.

25. Question: Why do we perspire before rains?
Answer: Before the rain falls, the atmosphere gets saturated with water vapors; as a result, the process of evaporation of sweat is delayed.

26. Question: How do birds sit safely on electric power lines?
Answer: This is possible because a bird only touches one line. If the bird were to touch another line or pole the electricity would travel through the bird, either to the ground or another wire.
Reply With Quote
The Following 2 Users Say Thank You to zuhaib ahmed For This Useful Post:
m ilyas shah (Wednesday, April 04, 2012), sara bhittani (Monday, August 06, 2012)
Old Monday, August 06, 2012
Join Date: Mar 2012
Location: Karachi
Posts: 442
Thanks: 206
Thanked 170 Times in 114 Posts
ssara will become famous soon enough

Members are requested to take a part. I will too.....Thanks.....
Reply With Quote
The Following User Says Thank You to ssara For This Useful Post:
zuhaib ahmed (Tuesday, August 07, 2012)
Old Tuesday, August 07, 2012
alihashmatkhoso's Avatar
Senior Member
Join Date: May 2012
Location: Karachi, now Lahore .
Posts: 773
Thanks: 431
Thanked 854 Times in 468 Posts
alihashmatkhoso has a spectacular aura aboutalihashmatkhoso has a spectacular aura aboutalihashmatkhoso has a spectacular aura about

Q.1 Fire due to petrol cannot be extinguished by pouring water over it why?
ANS.. this due to haviness of water, which ships down and petrol comes down and petrol comes on the surface and continues burning

Q.2 what will happen if the force of gravity disappear on earth ?
ANS.. all living objects of earth will float on the earth

Q.3 The gas usually filled in the electric bulb is?

ANS.. nitrogen

Q.4 Quartz crystals normally used in quartz clocks etc. is chemically?
ANS.. silicon dioxide

Q.5 The hardest substance available on earth is.?

Q.6 The variety of coal in which the deposit contains recognizable traces of the original plant material is.?

Ans.. peat

Q.7The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is?
ANS.. helium

Q.8 The gases used in different types of welding would include?
ANS.. oxygen and acetylene

Q.9 The average salinity of sea water is?
ANS.. 3.5%

Q.10 Heavy water is?
ANS..deuterium oxide

LOVE all, TRUST a few, do WRONG to none......
Reply With Quote
The Following 3 Users Say Thank You to alihashmatkhoso For This Useful Post:
memon bilal (Wednesday, August 15, 2012), NoorMBA (Thursday, August 09, 2012), zuhaib ahmed (Tuesday, August 07, 2012)

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Falsifiability of science and transcendentlism of religion sajidnuml Essays 1 Wednesday, September 02, 2015 08:36 PM
Principles of Political Science Xeric Political Science 8 Friday, December 02, 2011 12:19 AM
A list of branches of Science and their studies usman malik 65 General Science Notes 0 Tuesday, July 13, 2010 12:23 PM
Philosophy of Science A Rehman Pal Philosophy 0 Sunday, March 18, 2007 04:42 PM

CSS Forum on Facebook Follow CSS Forum on Twitter

Disclaimer: All messages made available as part of this discussion group (including any bulletin boards and chat rooms) and any opinions, advice, statements or other information contained in any messages posted or transmitted by any third party are the responsibility of the author of that message and not of (unless is specifically identified as the author of the message). The fact that a particular message is posted on or transmitted using this web site does not mean that CSSForum has endorsed that message in any way or verified the accuracy, completeness or usefulness of any message. We encourage visitors to the forum to report any objectionable message in site feedback. This forum is not monitored 24/7.

Sponsors: ArgusVision   vBulletin, Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.