Q&A - PSLE Science

[atutor2001]

isetan:

Hi atutor2001,


I come across such similar like questions in some assessment books. The answer is similar to the tutor's ans, ie no current will pass thru.

So I think such books also quite misleading.

Hi isetan
I agree with you. Quite a number of the assessment books have errors in their answers. Some times we can also find mistakes in the answer keys from schools. I think Primary Science syllabus is a bit too wide and each topic is not covered with enough depth. The range make it very tough for the children to remember and the lack of depth make it difficult for them to understand.

[BigDevil]

atutor2001:

BigDevil:

If a light bulb is connected to 3 batteries which are arranged in the following sequence:


[- +][- +][+ -]

Will the bulb light up? Note the 2nd and 3rd battery is connected +ve to +ve.

Niece's school teacher says yes. Tutor says no.

:faint:

For your case, electric current can still flow because the net voltage is that of 1 battery. The other 2 batteries that are opposing each other will just act as conductor of electricity. So the teacher is correct.

Thanks, atutor2001!

Guess it's time for her to change tutor.

[Michaelia0816]

BigDevil:

atutor2001:

[quote=\"BigDevil\"]If a light bulb is connected to 3 batteries which are arranged in the following sequence:


[- +][- +][+ -]

Will the bulb light up? Note the 2nd and 3rd battery is connected +ve to +ve.

Niece's school teacher says yes. Tutor says no.

:faint:

For your case, electric current can still flow because the net voltage is that of 1 battery. The other 2 batteries that are opposing each other will just act as conductor of electricity. So the teacher is correct.

Thanks, atutor2001!

Guess it's time for her to change tutor. [/quote]Similar like tha magnet, like poles and unlike poles. Haha!

[Michaelia0816]

Why when a magnet is attracted by a non-magnet object? I think it because of electro-magnet. Are my answer correct? I not so sure! Pls help me!!!

[cimman]

atutor2001:

isetan:

Hi atutor2001,


I come across such similar like questions in some assessment books. The answer is similar to the tutor's ans, ie no current will pass thru.

So I think such books also quite misleading.

Hi isetan
I agree with you. Quite a number of the assessment books have errors in their answers. Some times we can also find mistakes in the answer keys from schools. I think Primary Science syllabus is a bit too wide and each topic is not covered with enough depth. The range make it very tough for the children to remember and the lack of depth make it difficult for them to understand.

maybe it is a typo ? happens when no proof reading is done. Even in novels I notice spelling mistakes. Happens very often in Maths assessment books where the numbers are wrong.

[Michaelia0816]

Did help with a question!!!

Do all food chains contain the same number of organism? Give one example to support your answer.
( Pls. Use P6 syllabus!)

[tianzhu]

Michaelia0816:

Did help with a question!!!

Do all food chains contain the same number of organism? Give one example to support your answer.
( Pls. Use P6 syllabus!)

Hi

No.

A food chain is a series of organisms through which energy is transferred in the form of food.

plant ------ ant -------- spider -------- bird

plant ------ butterfly ------- bird

Best wishes

[Michaelia0816]

Thank a lot!

[Verysuperkiasu]

http://i39.tinypic.com/1zpo7td.jpg\">


Is the answer (3)? Though I wonder why should C be in the gaseous state?

A - can be solid or liquid as ice/water at 0 deg can be both until ice has completely melted then it will be completely liquid.

B - can be liquid or gas (same reasoning - water/steam at 100 deg can be liquid or gaseous until all the water has evaporated then it will be completely steam.

but C - at 28 deg, should be in the liquid state but cannot be gaseous state right? But (3) seems to be the best answer.

What is your answer and reason?

[Michaelia0816]

My answer is (3) too and my reason are because of Water Vapour as Evaporation happens all the time, at any temperature. The color on red means important and take note! Hopes it help!