If the current in an inductor is doubled, by what factor is the stored energy multiplied?
1.4
2.2
3.1
4.1/2
5.1/4
[Ques. 2] How is a rock defined?
[Ques. 3] A solenoidal inductor for a printed circuit board is being redesigned. To save weight, the number of turns is reduced by one-half, with the geometric dimensions kept the same. By how much must the current change if the energy stored in the inductor is to remain the same?
1.It must be four times larger.
2.It must be two times larger.
3.It should be left the same.
4.It should be one-half as large.
5.No change in the current can compensate for the reduction in the number of turns.
[Ques. 4] Distinguish between fluorescence and phosphorescence.
[Ques. 5] In Figure OQ32.4, the switch is left in position a for a long time interval and is then quickly thrown to position b. Rank the magnitudes of the voltages across the four circuit elements a short time thereafter from the largest to the smallest.
1.VL > V1200 > 12.0 V > V12
2.V1200 > VL > 12.0 V > V12
3.VL > V12 > 12.0 V > V1200
4.12.0 V > VL > V12 > V1200
5.V12 > 12.0 V > V1200 > VL
6.None of the above
[Ques. 6] Define and give an example of tenacity.
[Ques. 7] Distinguish between cleavage and crystal faces.
[Ques. 8] Two solenoids, A and B, are wound using equal lengths of the same kind of wire. The length of the axis of each solenoid is large compared with its diameter. The axial length of A is twice as large as that of B, and A has twice as many turns as B. What is the ratio of the inductance of solenoid A to that of solenoid B?
1.4
2.2
3.1
4.1/2
5.1/4
[Ques. 9] Discuss the crystalline structure of minerals.
[Ques. 10] A long, fine wire is wound into a coil with inductance 5 mH. The coil is connected across the terminals of a battery, and the current is measured a few seconds after the connection is made. The wire is unwound and wound again into a different coil with L = 10 mH. This second coil is connected across the same battery, and the current is measured in the same way. Compared with the current in the first coil, the current in the second coil is:
1.four times as large.
2.twice as large.
3.unchanged.
4.half as large.
5.one-fourth as large.
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