Basic Idea:

• Measure the stopping potential and binding energy for ejected electrons.

• 8

	What:	How Many:	Where:
Note: One Mercury source is used for two setups per bench!
	Pasco Mercury Light Source See photo below	1	non-Majors storeroom, shelf DD3
The following components are for each setup; there are up to two setups per lab bench!
	Light Aperture Assembly See photo below	1	non-Majors storeroom, shelf DD4
	Blazed diffraction grating See photo below	1	non-Majors storeroom, shelf DD4
	Photoelectric head (Units A, B, D, E, F, G, H, I) See photo below	1	non-Majors storeroom, shelf DD4
	Support base See photo below	1	non-Majors storeroom, shelf DD4
	Coupling bar See photo below	1	non-Majors storeroom, shelf DD4
	Filters: green, yellow and variable transmission See photo below	1 each	non-Majors storeroom, shelf DD4
	Light Block (optional - only needed when one side of Hg source is not used)	1	non-Majors storeroom, shelf DD4
	Digital Multimeter	1	Majors storeroom, locked in steel cabinet
	Wires	Three – 36" or 48" (1 red, 1 black, 1 purple or gray - if possible) Two – 24" (1 red, 1 black)	Bewkes 231 (Phys 152 Lab), Majors storeroom
	Flashlight	2	non-Majors storeroom, shelf CC3
The following power supplies are set up under right front bench; Ask Jeff if we're using Two single- or One Dual-power supply!
	Either: Dual power supply	1	Majors storeroom, shelf C2
	Or: 40v regulated power supply	2	Majors storeroom, shelf C2
	Digital Multimeter	1	Majors storeroom, locked in steel cabinet
	Wires	Two – 12" (1 red, 1 black) Three – 36" (1 red, 1 black, 1 purple or gray)	Bewkes 231 (Phys 152 Lab), Majors storeroom

Notes:

• Lab setup (photo details):
  • Place apparatus at an angle for easier access
  • Use photo heads in positions as shown
  • The grating must be installed with the label on the same side as the photo head wire connections (the thumb screw will be at the bottom); see these photos for orientation!

  

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• Mercury light source:

  
  Image courtesy PASCO Scientific.

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• Photoelectric head and filters: yellow, variable transmission and green

  
  Image scanned from PASCO Scientific catalog.

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• Light aperture assembly, support base, blazed diffraction grating, coupling bar:

  
  Image scanned from PASCO Scientific Instruction Manual.

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• The whole setup (two per mercury source):

  
  Image scanned from PASCO Scientific Instruction Manual.

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• Power supply connection:
  
  • Note: Main DC power panel must be disconnected before the power supplies are used! Jeff will take care of this.
  • Use one dual-power supply (set to independent), or two single-power supplies connected in series; both are set to 9.0 volts.
  • Power supplies are placed in cabinet under the lab bench (see photo details page!)

  Connection of Dual Power Supply	Connection of Two Single-Power Supplies

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• Photoelectric head power connection:
  • Note the additional ground wire connected to the green connector on the power panel. Only the newer photo heads require this connection, yet all will work properly when connected thusly.