Biologists use optical tweezers to manipulate micron-sized objects using a beam of light. in this technique, a laser beam is focused to a very small-diameter spot. because small particles are attracted to regions of high light intensity, the focused beam can be used to "grab" onto particles and manipulate them for various experiments. in one experiment, a 10 mw laser beam is focused to a spot that has a diameter of 0.67 μmpart a: what is the intensity of the light in this spot? part b: what is the amplitude of the electric field?

The space within which a test north pole experiences a force magnetic poles 2. a powerful stream of electrons flowing high above the earth in the ionosphere electrojet 3. a concept to explain the directional nature of a magnetic field field lines 4. coil of wire designed to produce a magnetic field by a current passing through its windings ionosphere 5. that region above the earth's atmosphere where particles exist in an ionized state magnetic field 6. the extremities of a magnet where the field lines tend to converge or concentrate aurora borealis 7. a phenomenon that occurs in the northern latitudes; the northern lights solenoid