In a circuit with a vibrating reed switch, a 5μF capacitor is charged from a battery of e.m.f. 16 V and completely discharged through a resistor with a frequency of 14 Hz. The average power dissipated as heat in the resistor is
A.80μW.B.256μW.C.600μW.D.9 mW.
The answer is D. But I don't know how to calculate. Pls help!!
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急! AL Phy Capacitor MC
2009-06-21 10:44 pm
回答 (1)
2009-06-21 11:18 pm
✔ 最佳答案
The energy dissipated as heat in the resistor E=(1/2)(CV^2)
=(1/2)(5μ)(16)^2
=0.63 mJ
The average power dissipated as heat in the resistor
=E*f
=(0.63m)(14)
=8.96 mW
Ans: D
2009-06-21 15:20:07 補充：
Note that half of the energy stored in the battery is for charging up of capacitor and another half is for dissipation as heat in the resistor .
收錄日期: 2021-04-22 00:44:55
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