BackFor some applications, it is important that the value of a resistance not change with temperature. For example, suppose you made a 3.60-k Ω resistor from a carbon resistor and a Nichrome wire-wound resistor connected together so the total resistance is the sum of their separate resistances. What value should each of these resistors have (at 0°C) so that the combination is temperature independent?
A 12 V car battery dies not so much because its voltage drops but because chemical reactions increase its internal resistance. A good battery connected with jumper cables can both start the engine and recharge the dead battery. Consider the automotive circuit of FIGURE P28.64. How much current is the dead battery alone able to drive through the starter motor?
A scientist measuring the resistivity of a new metal alloy left her ammeter in another lab, but she does have a magnetic field probe. So she creates a 6.5-m-long, 2.0-mm-diameter wire of the material, connects it to a 1.5 V battery, and measures a 3.0 mT magnetic field 1.0 mm from the surface of the wire. What is the material's resistivity?
A battery produces 40.8 V when 7.10 A is drawn from it, and 47.3 V when 2.80 A is drawn. What are the emf and internal resistance of the battery?
Which equation is correct according to Ohm's law?
How does increasing the resistance in a circuit affect the current flow, assuming the voltage remains constant according to ?
Which of the following best describes Ohm's Law?
Which set of physical quantities are directly related by Ohm's Law ?
Ohm's law describes the relationship between which of the following physical quantities?