You\'ve just had a beer (or maybe than one) and decide it\'s time to make a beer

Question

You've just had a beer (or maybe than one) and decide it's time to make a beer canpacitor. To do this you will take you empty shown at right, wrap the cylindrical portion with a layer of paper (K = 3.5, thickness = 0.27 mm) and then wrap a layer of aluminum foil over the paper. This will form a capacitor consisting of two concentric cylinders. epsilon_0 = 885 times 10^-12 C^2/N middot m^2 a Assume this case can be treated as a parallel plate capacitor (quite a good assumption as it turns out). What is the capacitance of your canpacitor? b The dielectric strength of the paper is 16 times 10^6 V/m. To what maximum voltage could you charge your capacitor safely? How much energy would be stored at this max voltage?

Explanation / Answer

Area

A=pi*D2/4 =pi*0.0652/4=3.32*10-3 m2

capacitance

C=KeoA/d=3.5*(8.85*10-12)*(3.32*10-3)/(12.5-0.54)*10-2

C=8.6*10-13 F

b)

Maximum voltage

V=Ed=(16*106)*(0.125-0.0054)=1.91*106 Volts

energy stored

U=(1/2)CV2=(1/2)*8.6*10-13*(1.91*106)2=1.574 J

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.