Demonstrating the motor effect? (1 Viewer)

[Michaelmoo]

Hey. I just have a question about the following dot point:

Perform a first hand investigation to demonstrate the motor effect

At school, we basically did an experiment which had a current carying wire hanging from 2 retort stands. We subjected it to a magnetic field and simply observed the Direction the wire moved.

However, I notice some text books conduct a similar experiment but instead they use a spring balanace to measure the magnitude and direction of the force on the wire, when subjected to a magnetic field.

Do you think that the experiment we did is enough to cover the dot point? Or should I revise the experiment such that the magnitude of the force is measured?

Thanks in advance.

 

[annabackwards]

At my school we used this method:

1. Clamp two strong bar magnets horizontally with opposite poles no more than a centimetre apart.
2. Suspend a wire vertically through the space between the magnets, so that its lower end is free to move.
3. Connect the ends of the wire to a DC power supply with light, flexible leads that allow the wire to move.
4. Switch the current on briefly, then off, observing any movement of the suspended wire. Any movement of the wire would demonstrate the motor effect.
5. Record the observations as diagrams.

I just left the experiment we did at school as we did it. The dot point asks for you do demonstrate it, not measure it so i'd just leave yours as you did it as well

 

[Michaelmoo]

Yer. The key word is demonstrate. I thought it was simply an observatin of the effect. Does anyone know thoguh if they've asked in the HSC anything to do with measuring the force?

Thanks.

 

[Aerath]

Yer. The key word is demonstrate. I thought it was simply an observatin of the effect. Does anyone know thoguh if they've asked in the HSC anything to do with measuring the force?

Thanks.

Yes, HSC 2005 Question 21.

 

[helper]

If you are asked to describe the investigation in the HSC, then you wouldn't have to have quantitative measurement.

However, looking at the section as a whole, you can be asked questions that are quantitative and based around an experiment. Like Q21 which isn't written on the assumption you have carried out the experiment. It is written to see if you can apply your knowledge.

 

[Michaelmoo]

Ok. But my question is that if they ask to describe the experiment, would you mention a step that involves measurign the force experienced by the wire (using a spring balance).. O and btw. Question 21 is a different prac and dot point, but still releavnt to this I guess. But it doesnt ask to describe the experiment.

 

[helper]

Basing it on the dot point, then if you have come up with an experiment that demonstrates the motor effect it is fine. It doesn't need to be quantitative for the HSC.
Last years Q15 is a similar style dotpoint and you had to 1. Have a working method. Clearly showed what you were changing and what you observed to demonstrate the effect.

In a school exam, they may require you to have quantitative data, if that's what you class did.

 

[Michaelmoo]

Nup. As I said, we simply observed if there was any movement of the wire, and the direction of the movement. We also checked if the movement was in compliance with the RHPR.

So it should be fine. Thanks.