9.4 From Ideas to Implementation – Practical Work

 

1. Discharge Tubes – Active Physics p261 – 262, Clearway Physics P198
1. Pressure & gas discharge tubes
2. Deflection in Crooke’s tubes
3. Dot position on CRO.

 

 

2. Photoelectric Effect
1. Computer animation on web page

 

 

1.      Start with lead as the target metal.

2.      Reduce the wavelength of the incoming light until photoelectrons begin to be ejected.

3.      Note the gradual colour changes for the light.

4.      Tabulate the energy of the electrons as you change the wavelength from 210nm to 110nm for every 10nm.

5.      Calculate frequency for this data.

6.      Plot energy of electrons Vs frequency of incident light for lead.

7.      Repeat for lithium between 400nm and 300nm.

8.      Find the maximum wavelength and the f₀ for each of the metals available and determine the work function for each metal. (hold the mouse down in the space between the end and the slider.)

9.      How is the energy of the electrons affected by the intensity of the light? How does it affect the number of photoelectrons?

 

 

 

 

3. Conductors
1. Conductors, Insulators and semi-conductors (diodes)
2. Use ammeter to evaluate conduction.

 

 

4. Electric Heaters
1. Coils in beakers
2. Vary materials and determine temperature increases.

 

 

5. Superconductors
1. Magnetic Levitation device – Local district physics excursion day.