A transformer has 22 turns of wire in its primary and 88 turns in its secondary. If 110 V ac is applied to the primary, what is the output potential difference?

If the number of secondary turns is 10 times the number of primary turns, and the input voltage to the primary is 6 volts, how many volts will be induced in the secondary coil?

The secondary oocyte leaving the follicle is in (a) interphase. (b) metaphase of the first meiotic division. (c) telophase of the second meiotic division. (d) metaphase of the second meiotic division.

A coil of 325 turns and an area of $19.5 \times 10^{−4} \mathrm{m}^{2}$ is removed from a uniform magnetic field at an angle of $45^{\circ}$ in 1.25 s. If the induced emf is 15 mV, what is the magnetic field’s strength?

A student attempts to make a simple generator by passing a single loop of wire between the poles of a horseshoe magnet with a $2.5 \times 10^{−2}$ T field. The area of the loop is $7.54 \times 10^{−3} \mathrm{m}^{2}$ and is moved perpendicular to the magnetic field lines. In what time interval will the student have to move the loop out of the magnetic field in order to induce an emf of 1.5 V? Is this a practical generator?

Why is a longer antenna needed to produce a low-frequency radio wave than to produce a high-frequency radio wave?

Electric guitar strings are made of ferromagnetic materials that can be magnetized. The strings lie closely over and perpendicular to a coil of wire. Inside the coil are permanent magnets that magnetize the segments of the strings overhead. Using this arrangement, explain how the vibrations of a plucked string produce an electrical signal at the same frequency as the vibration of the string.

Why does electromagnetic radiation obey the inverse-square law?

Where is the energy of an electromagnetic wave stored? Describe how this energy can be used.

By what factor do you multiply the maximum emf to calculate the rms emf for an alternating current? F. 2, G. $\sqrt{2}$, H. $\frac{1}{\sqrt{2}}$, J. $\frac{1}{2}$.

If you have a fixed magnetic field and a length of wire, how can you increase the induced emf across the ends of the wire?

What is the average value of current over one cycle of an ac signal? Why, then, is a resistor heated by an ac current?

Suppose a fixed distance separates the centers of two circular loops. What relative orientation of the loops will give the maximum mutual inductance? What orientation will give the minimum mutual inductance?

A voltage $V_{\mathrm{rms}}=110 \mathrm{~V}$ at a frequency of $60 . \mathrm{Hz}$ is applied to the primary coil of a transformer. The transformer has a ratio $N_{\mathrm{P}} / N_{\mathrm{S}}=11$. The secondary coil is used as the source of $V_{\text {emf }}$ for the filtered fullwave rectifier of Problem $30.56$. a) What is the maximum voltage in the secondary coil of the transformer? b) What is the DC voltage provided to the resistor?