Distinguish between ac and dc. When you plug a light bulb into a wall outlet, where is the source of electrons?
What will be an ideal response?
Answer: AC is alternating current, where electrons do not migrate but simply alternate about relatively fixed positions. In dc, the flow of electrons is in one direction only. Migration does occur, but the source of electrons, whether in a dc or ac circuit, is the electric conductor itself. You can buy a water pipe in a hardware store with no water inside, but you can't buy an electron pipe without its supply of electrons. Wires and all materials have electrons in them.
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Much of the solar wind comes from ____ where the magnetic field does not loop back into the sun
a. prominences b. coronal holes c. spicules d. granulation e. auroras
Velocity Selector: The figure shows a velocity selector that can be used to measure the speed of a charged particle. A beam of particles of charge +q is directed along the axis of the instrument. A parallel plate capacitor sets up an electric field E which is oriented perpendicular to a uniform magnetic field B. If the plates are separated by 3.0 mm and the value of the magnetic field is 0.30 T, what potential difference between the plates will allow particles of speed v = 5.0 × 105 m/s to pass straight through without deflection?
A. 450 V B. 1400 V C. 2800 V D. 140 V E. 70 V
A sled of mass 10. kg slides down a flat hill that makes an angle of 10.° with the horizontal. If friction is negligible, what is the resultant force on the sled?
What will be an ideal response?
In common transparent media, as the frequency of light increases, the index of refraction
A) increases. B) stays constant. C) decreases. D) varies as the sine of the incident angle.