Question

1) A parallel plate capacitor with an area of 300 cm2 is separated by a distance of 2 mm in air or vacuum is charged by a battery of 12 volts. Find

a) the capacitance of the system,

b) the charge on the plates and

c) the energy stored.

2) 2 capacitors , one 10 μF and the other 20 μF are connected in series to a battery of 12 volts.

Find

a) the equivalent capacitance of 2

b) the equivalent charge and on each capacitor

c) the voltage drop across each

d) the energy stored in each.

Answer 1

e Ginen A =3000m² = 0.0300 m2 d = 2 mm 0.002 m VE 12 Volts SA c= 8.95X/0-12 X 0.0300 Capacitanie d 0.002 Ic=1.3275X10 -10 a) (b ) Q = CV = 1.3275X/ 0x12 = 15.93 X/0-10 Coulomb Energy stored us _ cv2 U = x 1.3275 X10'0x(12)2 u= 95.5881010 J HHH TOUF (2 2011 F 12V (b) Equivalent pacitance, for series Connection Ciz ther = 1 + 1 → lega G+(2 10x 20 Cer Ceq = 6.67 MF 10+20 Q = Cear = 6.67x10-6 x 12 = 80 810-6), Coulomb Voltage drop LOWF,V, across roof. ₂ = 0 Energy stored in solfu, = 2 in rollf & 4₂ = 262 Tv. = 8v al TOSS 7/1₂ = 48 13.20x1010 J 1.60 81510 J