Question

Battery Identical Lightbulbs Initially, made of tungsten which has n-6e+28 e/m 3 and u-0.0018 (m/s)/(N/C). The radius of the filament is 4.1e-06 m. The capacitance of the capacitor is 0.8 F. The total length of the connecting wires is 9 cm. Before you answer the questions below, write down two correct Δν round trip (energy conservation) equations for this circuit. The equations should be general (that is, correct for all times after t-0 and not only applicable for a specific time). Your equations should contain the quantities Rbulb and C (the capacitance of the capacitor). the capacitor plates contain no charge. At time t-0, the switch is closed. The resistance of each bulb is 10 ohms and the emf of the battery is 11 V. The filament of each bulb is Use these equations to answer the following questions. a) Find/estimate the current through bulb B immediately after the switch is closed b) What is the charge on the capacitor immediately after the switch is closed? coulombs c) Find/estimate the current through bulb A three minutes after the switch is closed d) What is the characteristic time it takes for the capacitor to charge (the RC time constant of the circuit)? e) Select the curve that displays the general shape of the charge versus time in the capacitor. Note: you only have one submission for this part of the question. f) Select the curve that displays the general shape of the current versus time in the capacitor. Note: you only have one submission for this part of the question.

Answer 1

- Switch / Given 1. C=0.8F od 3 I After Sw © Battery - After Switch is I closed. loe Applying KUL for each mesh. 11 = Toli-ic) troi Immediately oh after loi = after switch switch is = is ? clos > closed then behawes capacitor as short circuit. Then los "v Lola charge on capacitor - immediately after the switch is closed is [czo ] we have in = - ] 8 B (e) Time Corstant of Circuit T = Rith a RH = le 11 lo = 512 capacitor charges completely after five constants te = 57 te= 5 Risc = 5 x 5*0.8 = 20 5 After changing completely it will be haves as open circuit. So after 3 minutes it will acts as open circuit ie Tezo Then i=i = 1.181 take capacitor fully it will 5 for changing time the Constants. T = Rpg C = 5x0.8 -48. te = 5T = 5 x 4 = 20$ (es. charge us time graph of Capacitor q= % [roetlee of current through Capacitur us time - - ---- -- i ar 3r 40 ST Tez is őtlec Sty 27+ YS PIN