Q&A - PSLE Science

[isetan]

Hi atutor2001,


Thanks for your help also!

[elkniwt]

Hi,


Need help in the following question :
http://i43.tinypic.com/23w2yb5.jpg\">

TIA

[tianzhu]

elkniwt:

Hi,


Need help in the following question :
http://i43.tinypic.com/23w2yb5.jpg\">

TIA

Hi

Beaker G has a constant rate of evaporation as its exposed area doesn’t change throughout the duration of the experiment.

However as beaker H is titled at an angle, its exposed area decreases as water evaporates from the beaker. Hence, its exposed surface area changes during the duration of the experiment. Thus the duration of the experiment affects the results.

Best wishes

[elkniwt]

Hi Tianzhu,


Thank you very much. Your explanation is very clear and precise. My dd will be able to understand. Thanks!

Regards.

[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:

[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:

Batteries are still conductor of electricity even when they are \"flat\" (but cannot be damaged like liquid flowing out) or when they are connected wrongly.

When connected wrongly, the voltages of 2 \"opposing\" batteries will \"cancel\" each other. Therefore, the final voltage will be zero if the number of batteries in one direction is the same as the number of batteries in the other direction (voltage of every battery is the same) and no electric current will flow. Current will not flow because there is no Potential Difference (voltage) in the circuit to push electric current round the circuit and not because that the circuit is OPEN. It is still a close circuit.

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.

[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.

[Michaelia0816]

Suggests me the suitable words!


Question:
Some of the energy is users by each organism itself to carry out a)______ b)______ such as respiration, movement, digestion and growth.

Thank a million!
( Based on Science Process Skill P5&6 Interaction Enviroment)

[Augmum]

Michaelia0816:

Suggests me the suitable words!


Question:
Some of the energy is users by each organism itself to carry out a)______ b)______ such as respiration, movement, digestion and growth.

Thank a million!
( Based on Science Process Skill P5&6 Interaction Enviroment)

life processes ?

[Michaelia0816]

My answer is basic processes, do u agree