Pei Hwa Presbyterian Primary

[Jennifer]

janet_lee88:

Jennifer:

This qn was accompanied by a diagram.


\"my son was tested on the advantages/disadvantages of using electromagnet in maglev train\"
was there a diagram provided?

There was a diagram for that question.

By chance, do you need have the qn to upload here? It will be very useful for us to understand what type of real-life qns will be used in exams

[dyh]

Jennifer:

abc123mama:

P5 science section B: my boy did an average job. Previously, he always lost marks because of incomplete description. This time, he had abnormal and creative thinking to the questions. For example, cage for pet mouse. He thinks if he uses glass, the mouse will be overheated.

I do not think your boy is wrong to think the hamster will die from heat.

The qn is too vague - a 1 dimensional diagram of a house with no windows or labels it is a open top whatsoever.

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

my son thought it is to do with heat too. but the paper stated \"temperature is constant\". so cannot argue with them.

[Jennifer]

S6169:

I think 2nd part of this this Q is wrong. when the switch is off, the spring metal (the conductor of electricity) still in contact, so the circuit is still a close circuit and everything is functioning.(electric induced magnetic force is still there).

What is the Model answer for the 1st part of the Q? From my boy, I think the answer also inaccurate.

a) The doorbell rang when the switch was closed, the circuit became closed. The iron core became an electromagnet which attracts the armature.

b) Even though the switch was turned off, the iron core remains a temporary magnet for a while, attracting the metal armature and closed the contact, thus making the circuit closed.

[S6169]

Jennifer:

abc123mama:

P5 science section B: my boy did an average job. Previously, he always lost marks because of incomplete description. This time, he had abnormal and creative thinking to the questions. For example, cage for pet mouse. He thinks if he uses glass, the mouse will be overheated.

I do not think your boy is wrong to think the hamster will die from heat.

The qn is too vague - a 1 dimensional diagram of a house with no windows or labels it is a open top whatsoever.

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

My son think it in the same way, so he left this Q a blank.
and he disagree with the model answer by thinking that not all plastic are transparent. :slapshead:

[Jennifer]

Jennifer:

S6169:

I think 2nd part of this this Q is wrong. when the switch is off, the spring metal (the conductor of electricity) still in contact, so the circuit is still a close circuit and everything is functioning.(electric induced magnetic force is still there).

What is the Model answer for the 1st part of the Q? From my boy, I think the answer also inaccurate.

a) The doorbell rang when the switch was closed, the circuit became closed. The iron core became an electromagnet which attracts the armature.

b) Even though the switch was turned off, the iron core remains a temporary magnet for a while, attracting the metal armature and closed the contact, thus making the circuit closed.

I do not like this qn- the diagram is too confusing at P5 level. Somemore the door bell is labelled not at the contacts which are the parts that will make the ringing sound.

[Jennifer]

dyh:

Jennifer:

I do not think your boy is wrong to think the hamster will die from heat.


The qn is too vague - a 1 dimensional diagram of a house with no windows or labels it is a open top whatsoever.

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

my son thought it is to do with heat too. but the paper stated \"temperature is constant\". so cannot argue with them.

A pet locked inside a car parked at an open space carpark will die from heatstroke even though the outside temperature is 30 deg C.

[janet88]

Jennifer:

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

:rotflmao: :rotflmao:
I also think the same thing...whatever material, the hamster will die.
Seriously, why ask such questions ?

[S6169]

Jennifer:

S6169:

I think 2nd part of this this Q is wrong. when the switch is off, the spring metal (the conductor of electricity) still in contact, so the circuit is still a close circuit and everything is functioning.(electric induced magnetic force is still there).

What is the Model answer for the 1st part of the Q? From my boy, I think the answer also inaccurate.

a) The doorbell rang when the switch was closed, the circuit became closed. The iron core became an electromagnet which attracts the armature.

b) Even though the switch was turned off, the iron core remains a temporary magnet for a while, attracting the metal armature and closed the contact, thus making the circuit closed.

The 2nd part of the Q mentioned that circuit will remain closed for a while? I think the circuit will remain closed untill the battery has run down.
For the 1st part of the Q, my son said the teacher mentioned about the resistance when she try to explain the answer.
Indeed, It is too complicated for a P5 student.

[Jennifer]

janet_lee88:

Jennifer:

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

:rotflmao: :rotflmao:
I also think the same thing...whatever material, the hamster will die.
Seriously, why ask such questions ?

The concept to be tested should be Properties of Materials - lightweight/transparent/breakable.

But the setter tries to be \"very creative\" lor, that's why came up with hamster instead of the usual fish tank scenario.

[Jennifer]

janet_lee88:

Jennifer:

I wrote a note : neither material is suitable. The hamster will either die of lack of oxygen or heatstroke.

:rotflmao: :rotflmao:
I also think the same thing...whatever material, the hamster will die.
Seriously, why ask such questions ?

there is a florist qn:

Florists would remove some leaves from their freshly-cut flowers before putting them in the containers for sale. Based on Alvin's experiment, explain why the florist would do that.

The less leaves the flowers have, the less amount of water it needs. therefore it helps them to save water in helping the flower survive.

The experiment was to see whether the number of leaves affects the amount of water being absorbed by the roots.