10. Consider the complex circuit shown. 200V 30022 3002 302 a 30022 2002 ww 3002 30Ω S w d 2102 www 2102 5 ΙΩ 6002 b 60V 4002 w 212 With S open: a. determine the current through the 1-2 resistor and 60-2 resistor. b. calculate AVed. Which end is at a higher potential? c. calculate the power delivered to the 3-2 resistor. With S closed: d. determine the current through the 1-2 resistor and 20-2 resistor. e. calculate AVac. Which end is at a higher potential? f. calculate the power supplied by the 200-V source.

A small office-building air conditioner operates or 408-V AC and consumes 50.0 kW. (a) What is its effective resistance? (b) What is the cost of running the air conditioner during a hot summer month when it is on 8.00 h per day for 30 days and electricity costs 9.00 cenls/kW h ?

Three identical 60.0-W, 120-V lightbulbs are connected across a 120-V power source as shown in Figure P28.72. Assuming the resistance of each lightbulb is constant (even though in reality the resistance might increase markedly with current), find (a) the total power supplied by the power source and (b) the potential difference across each lightbulb.

Consider the circuit below, (a) What is the initial current through resistor R2? when the switch is closed? (b) What is die current through resistor R2 when the capacitor is fully charged, long after die switch is closed? (c) What happens if the switch is opened after it has been closed for some rime? (d) If the switch has been closed for a time period long enough for the capacitor to become fully charged, and then the switch is opened, how long before the current through resistor R1 reaches half of its initial value?

Consider the circuit below. The capacitor has a capacitance of 10 mF. The switch is closed and after a long time the capacitor is fully charged, (a) What is the current through each resistor a long time after the switch is closed? (b) What is the voltage across each resistor a long rime after the switch is closed? (c) What is the voltage across the capacitor a long time after the switch is closed? (d) What is the charge on the capacitor a long time after the switch is closed? (e) The switch is then opened. The capacitor discharges through the resistors. How long from the time before the current drops to one fifth of the initial value?

A circuit contains a D-cell battery, a switch, a 20- resistor, and three 20-mF capacitors. The capacitors are connected in parallel, and the parallel connection of capacitors are connected in series with the switch, the resistor and the battery, (a) What is die equivalent capacitance of the circuit? (b) What is the KC time constant? (c) How long before the current decreases to 50% of the initial value once the switch is closed?

A 20.00-ohm; 5.00-watt resistor is placed in series with a power supply, (a) What is the maxim tun voltage that can be applied to the resistor without hanniug the resistor? (b) What would be the current through the resistor?

Integrated Concepts (a) An immersion heater utilizing 120 V can raise the temperature of a 1.00 102 -g aluminum cup containing 350 g of water from 20.0°C to 95.0°C in 2.00 min. Find its resistance, assuming it is constant during the process. (b) A lower resistance would shorten the heating time. Discuss the practical limits to speeding the heating by lowering the resistance.

A circuit contains a D cell battery, a switch, a 20- resistor, and four 20-mF capacitors connected in series, (a) What is the equivalent capacitance of the circuit? (b) What is the fiC time constant? (c) How long before the current decreases to 50% of the initial value once the switch is closed?

(a) Digital medical thermometers determine temperature by measuring the resistance of a semiconductor device called a thermistor (which has a= - 0.0600/°C ) when it is at the same temperature as the patient. What is a patient's temperature if the thermistor’s resistance at that temperature is 82.0% of its value at 37.0°C (normal body temperature)? (b) The negative value for a may not be maintained for very low temperatures. Discuss why and whether this is the case here. (Hint: Resistance can’t become negative.)