- By
**mills** - Follow User

- 65 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about 'PHYSICS EXAMINATIONS – 2006' - mills

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### PHYSICS EXAMINATIONS – 2006

Bruce Walsh

REMINDERS

- Calculators
- Study design and textbooks
- Examiners report
- VASS system
- SSMS

STATISTICS

- 6712 students
- Mean = 90 = 50%
- Std dev = 38.7 = 21.5%
- Number achieving 100% = 0

GENERAL COMMENTS

- Reasonably challenging paper
- Detailed studies
- Attempt ONE detailed study only
- Explanations address specific question. – Diagrams
- Show working

Converting units

- Calculations – powers of 10

- raising to power eg. R3

- Care reading scale on axes
- Multiple choice questions
- Illegible writing

PROBLEM AREASMOTION

- Q3. Two stage – get acc from F=ma then use const acc formula. Many assumed a=9.8. Few used W=ΔEK
- Q6. Net force. Many neglected gravity. Others added it instead of subtracting
- Q7. Multiple steps. Net force const. Use F=ma for acc then const acc for dist. OR I=Δp for speed then const acc for dist. Many assumed acc was g

Q8. Two components then Pythagoras. Multiple steps

- Q11. I=Δp or get acc then f=ma Easier to treat space station than shuttle (3rd law). Confusion over masses and speeds
- Q12. Conservation of energy. Some fudging

Q14. Conservation of energy. Loss of Grav PE = Gain in Spring PE. Many used F=-kx assuming f=mg at bottom

ELECTRONICS & PHOTONICS

- Q1. DC biasing. Parts 2 and 3 poorly done
- Q3. Signal voltage - clipping
- Q4. Decoupling capacitor. Most knew what it did but not why
- Q8. Modulation

RELATIVITY

- Q7-9. Confusion over frames of reference.

MATERIALS & STRUCTURES

- Q3. Reading axis ε=2% not 2
- Q4. Calculated wrong material or misread strain axis
- Q6. Work = Area of graph x Volume Many forgot volume or had calculation difficulties

FURTHER ELECTRONICS

- Q7. Operation of regulator

STATISTICS

- 6589 students
- Mean = 111 = 62%
- Std dev = 41 = 23%
- Number achieving 100% = 20

GENERAL COMMENTS

- Accessible paper
- Detailed studies
- Illegible writing
- Explanations must address specific question

Explanations – one mark per point

- Show working
- Unit conversions, eg. cm2 to m2
- Read questions carefully. Answer what is asked not what you expect to be asked.

PROBLEM AREASELECTRIC POWER

Q1. Sketching magnetic fields.

Q8. E.M. induction. Trouble calculating area (units) and getting correct time

Q14-15. Operation of transformer

Q16. Overall distribution system

LIGHT and MATTER

- Q1. Incoherent light from wide spectrum sources. Confused with discrete emission spectrum.
- Q2. Wave and particle predictions for PE effect.
- Q6. Meaning of standing waves for electrons in stable states in atoms.

Q11. Distinction between matter and electromagnetic radiation. Wrong Planck’s constant. Assumption that because momentum was the same, energy was also. Electron speed taken as 3x108.

SYNCHROTRON

- Q2. Explain two advantages.
- Q5. Relate greater wavelength to reduced energy.

PHOTONICS

- Q5. Operation of graded index multimodal fibres
- Q6-7. Snell’s law
- Q10. Rayleigh scattering increases as wavelength decreases.

SOUND

- Q6. Sound from front and rear out of phase, box prevents interference.
- Q9. Unable to explain resonance in terms of behaviour of sound waves.

Download Presentation

Connecting to Server..