14.2 Self-inductance and inductors  (Page 4/6)

Does self-inductance depend on the value of the magnetic flux? Does it depend on the current through the wire? Correlate your answers with the equation $N{\text{Φ}}_{\text{m}}=LI.$

Would the self-inductance of a 1.0 m long, tightly wound solenoid differ from the self-inductance per meter of an infinite, but otherwise identical, solenoid?

Discuss how you might determine the self-inductance per unit length of a long, straight wire.

The self-inductance of a coil is zero if there is no current passing through the windings. True or false?

How does the self-inductance per unit length near the center of a solenoid (away from the ends) compare with its value near the end of the solenoid?

An emf of 0.40 V is induced across a coil when the current through it changes uniformly from 0.10 to 0.60 A in 0.30 s. What is the self-inductance of the coil?

The current shown in part (a) below is increasing, whereas that shown in part (b) is decreasing. In each case, determine which end of the inductor is at the higher potential.

What is the rate at which the current though a 0.30-H coil is changing if an emf of 0.12 V is induced across the coil?

When a camera uses a flash, a fully charged capacitor discharges through an inductor. In what time must the 0.100-A current through a 2.00-mH inductor be switched on or off to induce a 500-V emf?

A coil with a self-inductance of 2.0 H carries a current that varies with time according to $I(t)=(2.0\text{A})\text{sin}120\pi t.$ Find an expression for the emf induced in the coil.

A solenoid 50 cm long is wound with 500 turns of wire. The cross-sectional area of the coil is ${2.0\text{cm}}^2$ What is the self-inductance of the solenoid?

A coil with a self-inductance of 3.0 H carries a current that decreases at a uniform rate $dI\text{/}dt=\mathrm{-0.050}\text{A/s}$ . What is the emf induced in the coil? Describe the polarity of the induced emf.

The current I(t) through a 5.0-mH inductor varies with time, as shown below. The resistance of the inductor is $5.0\text{Ω}.$ Calculate the voltage across the inductor at $t=2.0\text{ms},t=4.0\text{ms},\text{and}t=8.0\text{ms}$ .

A long, cylindrical solenoid with 100 turns per centimeter has a radius of 1.5 cm. (a) Neglecting end effects, what is the self-inductance per unit length of the solenoid? (b) If the current through the solenoid changes at the rate 5.0 A/s, what is the emf induced per unit length?

Suppose that a rectangular toroid has 2000 windings and a self-inductance of 0.040 H. If $h=0.10\text{m}$ , what is the ratio of its outer radius to its inner radius?

What is the self-inductance per meter of a coaxial cable whose inner radius is 0.50 mm and whose outer radius is 4.00 mm?