Agenerator is constructed by rotating a coil of n turns in a magnetic field b at a frequency f. the internal resistance of the coil is r and the cross sectional area of the coil is a.
true or false
the maximum induced emf occurs when the coil is rotated about an axis perpendicular to area a.
the average induced emf doubles if the magnetic field b is doubled.
the average induced emf doubles if the resistance r is doubled.
the average induced emf doubles if the frequency f is doubled.
the average induced emf doubles if the area a is doubled.

The particle in a two-dimensional well is a useful model for the motion of electrons around the indole ring (3), the conjugated cycle found in the side chain of tryptophan. we may regard indole as a rectangle with sides of length 280 pm and 450 pm, with 10 electrons in the conjugated p system. as in case study 9.1, we assume that in the ground state of the molecule each quantized level is occupied by two electrons. (a) calculate the energy of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels. 9.27 electrons around the porphine ring (4), the conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. we may treat the group as a circular ring of radius 440 pm, with 20 electrons in the conjugated system moving along the perimeter of the ring. as in exercise 9.26, assume that in the ground state of the molecule quantized each level is occupied by two electrons. (a) calculate the energy and angular momentum of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

Current from a charged capacitor lights a bulb. as time goes on the brightness of the