1. [0/2 Points] DETAILS PREVIOUS ANSWERS MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Consider the circuit shown in the figure below, where R, = 3.00 0, R2 = 6.00 0, and & = 12.0 v. 10.0 0 R2 5.00 0 2.00 0 R1 WW 3 (a) Find the voltage (in V) across R1. X Find the equivalent resistance in the circuit by applying the equations for resistances in series and parallel, and use your result and Ohm's law to determine the total current in the circuit. You can use this value to calculate the potential drop across the 2.00-0 resistor, and from this, find the voltage across R1 . V (b) Find the current (in A) in R1.2. [-/3 Points] DETAILS MY NOTES ASK YOUR TEACHER PRACTIC In the circuit of the figure below, the switch S has been open for a long time. It is then suddenly closed. Take & = 10.0 V, R, = 41.0 kQ, R, = 140 kQ2, and C = 11.5 pF. R1 3 s R2 a) Determine the time constant before the switch is closed. s b) Determine the time constant after the switch is closed. (c) Let the switch be closed at t = 0. Determine the current in the switch as a function of time. (Assume I is in A and t is in s. Do not enter units in your expression. Use the following as necessary: t.) I =3. [-1'2 Points] DETAILS The resistors in the circuit below have the following values: R1 = 7.90 , R2 = 7.00 , and R3 = 3.60 R. The two batteries each have a voltage of 5.00 V. R3 52 (a) Find the current in through R3. E A [b] How much power do the batteries deliver to R3? :lw 4. [42 Points] DETAILS Suppose you wish to fabricate a uniform wire from 2.30 g of copper. The IMire is to have a resistance of R = 0.640 [1 and all the copper is to be used. (a) What must be the length of this wire? :m [b] What must be the diameter of this wire? :um 5. [-fZPoints] - The quantity of charge q (in coulombs) that has passed through a surface of area 1.90 cm 2 varies with time according to the equation q = 4:3 + 3f + 5, where f is in seconds. (a) What is the instantaneous current through the surface at t = 0.950 s? |:| A (b) What is the value of the current density? |:|Wm1