25.54 In the circuit shown in Figure P25.54 Fig. P25.54, R is a variable resistor whose value ranges from 0 to oo, and a and bare the terminals of a battery that has an emf € = 15.0 V and an internal resistance of 4.00 2. The ammeter and voltmeter are idealized meters. As R varies over its full range of values, what will be the largest and smallest readings of (a) the voltmeter and (b) the ammeter? (c) Sketch qualita- tive graphs of the readings of both meters as functions of R. (A) SATZ R

The capacitance of a parallel-plate capacitor is proportional to the area of its plates and inversely proportional to the plate separation. O True O False The drift speed of electrons in a copper wire carrying 10 A current is much greater than 1 m/sec. O True O False The electric power dissipated in a resistor is eventually converted to kinetic energy of charges. O True O False

none of the preceding DETAILS SHIPPS15 8.2.E.020. Two resistors with values of 29 0 and 45 0, respectively, are connected in parallel and hooked to a 18 V batte (a) What would be the current in the circuit? A (b) What would be the power expended in the circuit? W DETAILS SHIPPS15 8.2.E.018. A 13.0 W LED light bulb is turned on. It has an operating voltage of 120 V. (a) How much current (in A) flows through the bulh?

Find (a) the equivalent resistance of the circuit in Figure P28.60, (b) the potential difference across each resistor, (c) each current indicated in Figure P28.60, and (d) the power delivered to each resistor.

The brightness of a lightbulb is dependent on the current that goes through the lightbulb (in reality on the power, which is I^2/R). In Europe, the voltage used is 220 Volts, as opposed to the 120 Volts used in the USA. Will a lighbulb that is made for European voltage work well or poorly in the USA?     It will work poorly in the USA. Since I=V/R, if V decreases, so does I, and so does the brightness.     It will work more efficiently in the USA. Since I=V/R, if V decreases, I increases, and the brightness increases.     It will work better in the USA because the resistance of the wires is smaller.     Whether it works better or worse depends on how modern the wiring system is, regardless of the voltage, V.

In the circuit shown in Figure OQ28.12, each battery is delivering energy to the circuit by electrical transmis­sion. All the resistors have equal resistance. (i) Rank the electric potentials at points a, b. c, d, and e from highest to lowest, noting any cases of equality in the ranking. (ii) Rank the magnitudes of the currents at the same points from greatest to least, noting any cases of equality.