Exam 9: Alternating-Current Circuits

A 5-µF capacitor is charged to 30 V and is then connected across a 10-µH inductor. The frequency of oscillation of the energy stored in the electric field of the capacitor and the magnetic field of the inductor is

For an inductor, the

For a capACitor, the

You place a 50-mH inductor across an AC generator that has a maximum EMF of 120 V. The inductive reactance when the frequency is 2.0 kHz is approximately

A 15- $\Omega$ resistor is connected ACross a sinusoidal source that has a peak value of 75 V. The average power delivered by this source is approximately

A circuit contains a capacitor (C $\mu$ F), an inductor (L mH), and an ohmic resistor (R $\Omega$ ) connected in series. If you change the potential across this series combination, the values that change (if you neglect thermal effects) are

A circular coil with 20 turns and radius 5 cm is rotated in a uniform magnetic field of 3.2 T. If the maximum voltage induced in the coil is 5 V, calculate the number of rotations of the coil per minute.

Use the following figure for the next three problems. The battery has a voltage V = 6 V, the inductance of the inductor L = 12 mH and the capacitance of the capacitor C = 8 $\mu$ F. Assume that the inductor and the wires have zero resistance. -The switch S was at position a for a long time when it is switched to b. What is the charge on the capacitor at t = 0.487 ms?

You connect a 250- $\Omega$ resistor, a 1.20-mH inductor, and a 1.80-pF capacitor in series across a 60.0-Hz, 120-V (peak) source. The Q factor for this circuit is approximately

A circular coil of radius 10 cm and a separate square coil of side 20 cm are both rotated in a magnetic field of 1.5 T. If the circular coil is rotated at a frequency of 60 Hz, then at what frequency must the square coil be rotated in order for both coils to have the same maximum induced voltage?

A square coil with 12 turns and side 5 cm is rotated in a uniform magnetic field of 1.2 T at an angular frequency of 90 radians per second. What is the maximum voltage induced in the coil?

If you double the frequency in the circuit shown, the inductive reactance of the inductor

Two heaters are plugged into the same 120-V AC outlet. If one heater is rated at 1100 W, then what can be the maximum rating of the second heater in order not to exceed the 20 A trip rating on the circuit?

The reACtance of an inductor is 100 $\Omega$ at 2 kHz. The inductance of this inductor is

You want the output current from the secondary coil of a transformer to be 10 times the input current to the primary coil. The ratio of the number of turns N₂/N₁ must be

A motor sometimes burns out when its load is suddenly increased because the resulting sudden decrease in its rotational frequency causes

The differential equation for this circuit is L dI/dt + Q/C = 0 Because I = dQ/dt, the solution is

At what frequency would the reactance of a 1.0-mH inductor be twice that of a 10- $\mu$ F capacitor?

At what frequency would the reactance of a 10-µF capacitor be 100 $\Omega$