2. A vacuum cleaner runs on a current of 12 amperes. How long will it take for 5

Question

2. A vacuum cleaner runs on a current of 12 amperes. How long will it take for 5.0 microcoulombs of charge to flow through it?

3. Conducting objects can be chrome-plated by immersing them in an electrolytic bath having positive chromium ions in solution. Each ion carries a charge of +e, and the object to be plated, say an automobile bumper, is wired as the negative electrode in the bath. A positive electrode is also placed in the bath, and as current flows between the two electrodes, chromium ions get deposited on the negative electrode (the bumper). If 0.186 kg of chromium is deposited on a bumper in 105 min, what is the current passing through the bath? The molar mass of chromium is 0.0520 kg.

4. In one of Bill Cosby's comedy routines, he talks about being so tired that "I turned off the light switch, and I was in my bed before the light went out!" Suppose the drift speed of electrons in the wiring of the Cosby household is 3.0×10-4 m/s, and that there are 3.2 m of wiring between the light switch in his bedroom and the lamp. (a) In a direct current circuit, where the current flows one way, how long would it take a conduction electron to go from the switch to the lamp? (b) Even though Cosby couldn't really have gotten into bed before the light went out, could he at least have gotten into bed before one electron had traveled from the switch to the lamp?

Explanation / Answer

2. time = charge / current = 5 x 10^-6 / 12 = 4.167 x 10^-7 second 3. number of moles = 186 grams / 52 grams/mol = 3.577 moles of chromium number of atoms = 3.577 * 6.022 x 10^23 = 21.54 x10^23 atoms charge = 21.54 x 10^23 atoms * 1.60 x 10^-19 coulomb per atom = = 344644 coulomb current = charge / time = 344644 coulomb / 6300 seconds = 54.7 amps

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.