Figure OQ31.2 is a graph of the magnetic flux through a certain coil of wire as a function of time during an interval while the radius of the coil is increased, the coil is rotated through 1.5 revolutions, and the external source of the magnetic field is turned off, in that order. Rank the emf induced in the coil at the instants marked A through E from the largest positive value to the largest-magnitude negative value. In your ranking, note any cases of equality and also any instants when the emf is zero.
1.C = D > B = A > E
2.E > A = B = 0 > C > D
3.A > B > D > C > E
4.E > A > B = D = 0 > C
[Ques. 2] State Bernoulli's principle.
[Ques. 3] Ask yourself a question concerning the unknown beyond our universe. If you wish, answer the question.
[Ques. 4] How big is the universe? You calculated the radius of the Hubble Volume (the observable universe) in Procedure 3 . Is it possible to calculate the radius of the entire (everything that is) universe? Justify your answer. (Hint: Consider the expansion rate.)
[Ques. 5] If we assume space to be infinite, what is the possibility of multiple universes where the laws of physics may be different than those of our universe?
[Ques. 6] Solenoid A has length L and N turns, solenoid B has length 2L and N turns, and solenoid C has length L/2 and 2N turns. If each solenoid carries the same current, rank the magnitudes of the magnetic fields in the centers of the solenoids from largest to smallest.
1.C > A > B
2.A > B > C
3.B > C > A
[Ques. 7] How are the Tully-Fisher calculations for the distance to a galaxy different from those used for spectroscopic parallax?
[Ques. 8] Rank the magnitudes of the following magnetic fields from largest to smallest, noting any cases of equality.
(a) the field 2 cm away from a long, straight wire carrying a current of 3 A
(b) the field at the center of a flat, compact, circular coil, 2 cm in radius, with 10 turns, carrying a current of 0.3 A
(c) the field at the center of a solenoid 2 cm in radius and 200 cm long, with 1 000 turns, carrying a current of 0.3 A
(d) the field at the center of a long, straight, metal bar, 2 cm in radius, carrying a current of 300 A
(e) a field of 1 mT
1.a > e > b > d > c
2.e > d > b > c > a
3.e > c > b > a > d
4.e > c > b > a > d
5.b > c > d > a > e
[Ques. 9] What is the relation between galaxy brightness and the width of the emission lines?
[Ques. 10] A uniform magnetic field is directed along the x axis. For what orientation of a flat, rectangular coil is the flux through the rectangle a maximum?
1.It is a maximum in the xy plane.
2.It is a maximum in the xz plane.
3.It is a maximum in the yz plane.
4.The flux has the same nonzero value for all these orientations.
5.The flux is zero in all cases.
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