Electric Force, Field, and Potential unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Superposition of fields
Conductors vs insulators
Field of a point charge
Electric field
Electroscope behavior
Grounding
Equipotential lines
Field line rules
Field inside a conductor
Potential difference and work
Coulomb's law
Charged particle released in a uniform field
Short answer 1. Define or explain: Sketching equipotentials
3 ptsShort answer 2. Define or explain: Uniform field between parallel plates
3 ptsShort answer 3. Define or explain: Field vs potential
3 ptsShort answer 4. Define or explain: Electric potential energy
3 ptsFree response
10 ptsThis course has no free-response prompt tagged to this unit, so one from elsewhere in the course is used. It is still worth writing — the skill transfers.
Monochromatic light of wavelength 550 nm illuminates two narrow slits separated by 0.25 mm. An interference pattern appears on a screen 3.0 m away.
State the condition for a bright fringe in terms of the path difference, and derive the expression for the spacing between adjacent bright fringes on the screen using the small-angle approximation.
Calculate that fringe spacing.
The source is replaced with red light of wavelength 700 nm. State and justify what happens to the spacing.
The slit separation is then doubled. State and justify what happens to the spacing.
Explain what this experiment demonstrates about the nature of light, and identify one experiment whose result cannot be explained by the same model.