If the resistance in a circuit is increased, what must also be increased to get the same amount of current through the circuit?

When working with high-power electric circuits, it is advised that whenever possible, you work "one-handed” or “keep one hand in your pocket." Why is this a sensible suggestion?

When the current in the portion of the circuit shown in Figure P32.65 is 2.00 A anti increases at a rate of 0.500 A/s, the measured voltage is Vab = 9.00 V. When the current is 2.00 A and decreases at the rate of 0.500 A/s. the measured voltage is Vab = 5.00 V. Calculate the values of (a) I. and (b) R

Consider the circuit below. The battery has an emf of = 30.00 V and an internal resistance of r = 1,00 . (a) Find the equivalent resistance of the circuit and the current out of the battery. (b) Find the current through each resistor, (c) Find die potential drop across each resistor, (d) Find the power dissipated by each resistor, (e) Find the total power supplied by the batteries.

When operating on a 120-V circuit, an electric heater receives 1.30 103 W of power, a toaster receives 1.00 103 W, and an electric oven receives 1.54 103 W. If all three appliances are connected in parallel on a 120-V circuit and turned on, what is the total current drawn from an external source? (a) 24.0 A (b) 32.0 A (c) 40.0 A (d) 48.0 A (e) none of those answers

The power dissipated in a resistor is given by P = V2/R, which means power decreases if resistance increases. Yet this power is also given by P = I2R, which means power increases if resistance increases. Explain why there is no contradiction here.

The immediate cause of many deaths is ventricular fibrillation, an uncoordinated quivering of the heart, as opposed to proper beating. An electric shock to the chest can cause momentary paralysis of the heart muscle, after which the heart will sometimes start organized beating again. A defibrillator is a device that applies a strong electric shock to the chest over a time of a few milliseconds. The device contains a capacitor of a few microfarads, charged to several thousand volts. Electrodes called paddles, about 8 cm across and coated with conducting paste, are held against the chest on both sides of the heart. Their handles are insulated to prevent injury to the operator, who calls Clear! and pushes a button on one paddle to discharge the capacitor through the patient's chest Assume an energy of 3.00 102 W s is to be delivered from a 30.0-F capacitor. To what potential difference must it be charged?

The terminals of a battery are connected across two resistors in parallel. The resistances of the resistors are not the same. Which of the following statements is correct? Choose all that are correct. (a) The resistor with the larger resistance carries more current than the other resistor. (b) The resistor with the larger resistance carries less current than the other resistor. (c) The potential difference across each resistor is the same. (d) The potential difference across the larger resistor is greater than the potential difference across the smaller resistor. (e) The potential difference is greater across the resistor closer to the battery.

A battery with an internal resistance of 10.0 produces an open circuit voltage of 12.0 V. A variable load resistance with a range from 0 to 30.0 is connected across the battery. (Note: A battery has a resistance that depends on the condition of its chemicals and that increases as the battery ages. This internal resistance can be represented in a simple circuit diagram as a resistor in series with the battery.) (a) Graph the power dissipated in the load resistor as a function of the load resistance. (b) With your graph, demonstrate the following important theorem: The power delivered to a load is a maximum if the load resistance equals the internal resistance of the source.

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.