Use the exact values you enter to make later calculations. Two capacitors C1 = 7

Question

Use the exact values you enter to make later calculations. Two capacitors C1 = 7 mu F and C2 = 28 mu F are independently charged to voltages V1 = 18 V and V2 = 54 V respectively. (When entering units, use micro for the metric system prefix mu .) The capacitors are then connected In parallel as shown In the diagram below. Once equilibrium Is reached, what are the magnitudes of the charges on the two capacitors? What Is the potential difference across each capacitor? Instead of connecting the positive plate of C1 to the positive plate of C2 the two capacitors are connected as shown below. Note that the positive plate of one Is connected to the negative plate of the other.

Explanation / Answer

a)

Both capacitors are in parallel

V=(C1V1+C2V2)/(C1+C2)

V=(7*18+28*54)/(7+28)

V=46.8 V

i)

Q1=C1V=7u*46.8 =327.6uF

Q2=C2V=28u*46.8 =1301.4uF

ii)

V1=V2=46.8 V

b)

if terminals of one capacitor are reversed

V=|(C1V1-C2V2)|/(C1+C2)

V=|(7*18-28*54)|/(7+28)

V=39.6 V

Q1=C1V=7u*39.6=277.2uF

Q2=C2V=28u*39.6=1108.8uF

V1=V2=39.6V

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

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